CN103680759A

CN103680759A - Method for producing oxide superconductor, and oxide superconductor

Info

Publication number: CN103680759A
Application number: CN201310388392.9A
Authority: CN
Inventors: 荒木猛司; 林真理子; 福家浩之
Original assignee: Toshiba Corp
Current assignee: Toshiba Corp
Priority date: 2012-08-31
Filing date: 2013-08-30
Publication date: 2014-03-26
Also published as: JP2014047100A; TW201422561A; JP5649626B2; EP2704224B1; TWI538896B; EP2704224A1; US20140066311A1; KR101476551B1; KR20140029246A

Abstract

Provided is a method for manufacturing an oxide superconductor, including preparing a coating solution containing alcohols including methanol as a solvent, the coating solution dissolving fluorocarboxylic acid salts including trifluoroacetates, the trifluoroacetates including a metal, barium and copper, the metal being selected from yttrium and lanthanoid metals (provided that cerium, praseodymium, promethium, and ruthenium are excluded); adding a substance of formula: CF 2 H-(CF 2 ) n -COOH or HOCO-(CF 2 ) m -COOH (wherein n and m represent positive integers) as a crack preventing chemical to the coating solution; forming a gel film on a substrate using the coating solution having the crack preventing chemical added thereto; forming a calcined film by calcining the gel film at an oxygen partial pressure of 3% or less in a process that is maintained at 200 DEG C or higher for a total time of 7 hours or less; and forming an oxide superconductor film by firing and oxygen anneal of the calcined film.

Description

The manufacture method of oxide superconductor and oxide superconductor

The Japanese patent application of the application based on proposing on August 31st, 2012 advocated priority No. 2012-190763, here cites and adds its full content.

Technical field

The present invention relates to manufacture method and the oxide superconductor of oxide superconductor.

Background technology

High-temperature superconductor is to have than thinking in theory the general name of metal oxide of the Tc that the metal series superconducting material of superconducting transition temperature (Tc) below 39K is higher.Oxide superconductor was the earliest found in 1986, passed through approximately 25 years, progressively realizing oxide superconductor is applied to superconducting power transmission cable, fusion reactor, magnetic suspension train, accelerator, magnetic diagnostic device (MRI) even if etc. comprise that cooling cost also has in the main equipment of advantage.

In oxide superconductor, mainly contain bismuth system, yttrium system, mercury/thallium superconductors etc., but in the magnetic field of liquid nitrogen temperature, bring into play the highest characteristic and do not need the yttrium series superconducting material of noble metal to attract most attention in recent years.

In the manufacture method of yttrium series superconducting material, since about 2000 rapidly its influence power of expansion be the MOD method of using trifluoroacetate, be so-called TFA-MOD(Metal organic deposition using trifluoroacetates: utilize the metal organic deposit of trifluoroacetate) method.Thereby this manufacture method is to use fluorine to make the yttrium series superconducting material reproducibility of growing in liquid phase obtain well the method for the orientation of atomic level.In addition, the method does not only need vacuum plant, and film forming and formation superconduction carry out respectively, so technology controlling and process is easy, has and can stably obtain the such feature of superconducting wire.

The greatest problem of TFA-MOD method is the thick-film of film.Only once be coated with and will crack, be difficult to thick-film, therefore studied for example by being repeatedly coated with thick-film.In addition, studied and for example added Anti-cracking agent and carry out thick-film.

In oxide superconductor, mainly contain bismuth system, yttrium system, mercury/thallium superconductors etc., but in the magnetic field of liquid nitrogen temperature, bring into play the highest characteristic and do not need the yttrium series superconducting material of noble metal to attract most attention in recent years.Be called as silver more than the bismuth series superconductive wire needs 60 volume % of 1st generation, cancelled successively manufacture.The sales volume of a contract of yttrium series superconducting material of 2nd generation has just surpassed 10 years above totals of 1st generation and has sold length of wires, for practical expectation, improves.

For mercury/thallium is oxide, although Tc is very high value more than 130K, even cooling, characteristic can not improve yet, and is that oxide is compared with yttrium, and the current density obtaining in liquid nitrogen temperature is little, from the viewpoint of practicality, considers to have problem.In addition, the iron arsenic of recent findings is that the Tc of oxide is more than K(60K more than 60 and lower than 70K), in liquid nitrogen, do not work.Existing problems aspect characteristic.

This yttrium series superconducting material is by YBa ₂cu ₃o _7-xcomposition represent, refer to the superconductor with perovskite structure, the oxide (wherein not comprising a part of element) that replaces the rare earth element there is group of the lanthanides in yttrium also shows superconducting characteristic.As its manufacture method, pulsed laser deposition, liquid growth sedimentation, electron beam (EB) method, deposition of metal organic (MOD) method etc. have been used so far.

In these manufacture methods, since about 2000 rapidly its influence power of expansion be the MOD method of using trifluoroacetate, be so-called TFA-MOD(Metal organic deposition using trifluoroacetates: the metal organic deposit method of utilizing trifluoroacetate) method.MOD method is in the past solid state growth in the situation that not using fluorine, thereby and above-mentioned manufacture method is to use fluorine to make the yttrium series superconducting material reproducibility of growing in liquid phase obtain well the method for the orientation of atomic level.The method does not only need vacuum plant, and film forming and formation superconduction carry out respectively, so technology controlling and process is easy, has and stably obtains the such feature of superconducting wire.In addition, by liquid growth, can be without vacuum in the situation that reproducibility obtain well the orientation of hundreds of meters of atomic levels, this is also the surprising method of finding first in mankind's history.In addition, thereby it is for carrying out the technique of graph thinning volume production after the wire rod of large width can being burnt till, and approaches 100% the market share relevant in Contract basis when this is considered to 2012.

The method comes from that ((1987), 1753-1755) and via BaCO for P.M.Mankiewich, et al.Appl.Phys.Lett.51 by EB method ₃situation under make superconductor method, ensuing 1 year, (the A.Gupta such as Gupta, et al.Appl.Phys.Lett.52, (1988), 2077-2079) attempt by the same precursor of the precursor phase of cheap MOD method making and Mankiewich etc., this has tried to become the trial of initial TFA-MOD method.

For the superconductor obtaining for making such as Gupta, infer that being therefore subject to being considered to reason is the sediment of poor solubility, the puzzlement of impurity because the basis of initiation material is different, superconducting characteristic is only 1/100 left and right of Mankiewich.Therefore, do not realize the orientation tissue of the atomic level based on liquid growth of the script that TFA-MOD method shows, predict that it forms the superconductor of low characteristic.

In order to eliminate this poor solubility, by raw material unified for the acetate Cima that is MIT teach group McIntyre etc. (P.C.McIntyre, et al.J.Appl.Phys.71, (1992), 1868-1877).Thus, obtained the superconductor that the superconductor of characteristic and Mankiewich etc. is roughly equal to.Afterwards, although detailed content is not clear, but at 1998 annual reports, deliver (J.A.Smith by the Smith of Cima professor group etc., et al.IEEE Trans.on Appl.Supercond., 9, (1999), 1531-1534) thickness can be the technology of 1 μ m, TFA-MOD method was studied energetically since about 1999.

The greatest weakness of TFA-MOD method is to be considered to once be coated with to form thicklyer.The superconduction critical electric current value of superconducting wire under liquid nitrogen is very important, because the increase of thickness is relevant to low cost, so developing energetically.About this thick-film, above-mentioned Smith etc. have delivered by controlling technique and have increased thickness, but in supplementary test in highly purified solution, critical film thickness is 0.30-0.35 μ m.Critical film thickness refers to the maximum film thickness obtaining in optimum process, with to only by change technique with regard to having realized the explanation of thick film, there is contradiction.In the experiment of Smith etc., mix and have certain impurity, it is effective for preventing crackle, can think and have the possibility of the thickness of realizing 1 μ m.

For the thick-film in TFA-MOD method, the crack technology that prevents when volume slip reaches 80～90% pre-burning is vital.The critical film thickness of the superconducting film of film forming in high purity solutions of TFA-MOD method is only 0.30 μ m, and the film forming of 0.35 μ m, easily cracks, and reproducibility reduces.

For this problem, Rupich etc. are mainly contain-(CH of use in the invention (EP1334525B1) of 2000 ₂) _n-Anti-cracking agent carry out thick-film.It is conventional gimmick that the organic method that hydrocarbon is main chain is take in interpolation in MOD method in the past.

But, while applying the method in TFA-MOD method, think and mainly aspect following, can have problems.The fluorine of trifluoroacetate easily with-(CH ₂) _n-H-H reaction, by this chemical reaction, the carbon atom at easy residual center.In addition, can think that molecular weight is little, reaction and the Cu composition that likely can distil are deposited in the top of film at low temperatures, contrary heavier Ba composition is deposited in bottom.

The atomic weight of the metallic element closing with trifluoroacetic acid base key is less more easily to be moved.For the trifluoroacetic acid copper distillation that prevents that molecular weight is minimum when the pre-burning, and McIntyre etc. (P.C.McIntyre, et al., Mat.Soc.Symp.Proc.169, (1990), 743-746) have carried out the formation of oligomer by partial hydrolysis.Can think that contrary heavier Ba component segregation, in film bottom, in the TEM image of the cross section of part test, has also occurred this tendency.

TFA-MOD method forms liquid phase when main burning, therefore can expect to eliminate the segregation in pre-burning film.But, from various experiments, the poor fluidity of this liquid phase, displacement less than 10～20nm.Also residual less than eliminating after the main burning that forms liquid phase to be once coated with the many pre-burning films in the resulting space of thick-film, be also this reason.In the formation of accurate liquid layer (pseudo-liquid phase), need to there are three kinds of metallic elements with the concentration of regulation.If the segregation of metallic element is large, when main burning, do not form accurate liquid phase itself, cannot make the perovskite structure of superconductor, superconducting characteristic reduces.Therefore, at-(CH ₂) _n-thick-film mode in, be 0.6 about μ m, characteristic reduces, and can think more unstable in 0.8 μ m characteristic.So long as a small amount of sample, just likely with thick film acquired character, but for the long size band of 500m, 1000m, the characteristic between both ends is difficult to realize.This is because the characteristic reduction at a place midway can cause reducing with whole characteristic.

In the technology of Rupich etc., can think due to segregation, can reach on the thickness of superconduction and be limited to 0.6～0.8 μ m.Therefore, need further to rely on current value, so developed, utilize the thick-film that coating is carried out repeatedly.But, be repeatedly coated with thick-film and produced other problems.Owing to forming gel mould on primary film forming layer top, and form the film forming layer of the 2nd time and carry out pre-burning heat treatment, so lower floor,, there is easily unstable such shortcoming of characteristic in the thermal history that is just subject to more and more.In addition, this technology is also at the interface formation heterosphere of layers 1 and 2 or the technology (M.Rupich of the reduction many factors of the characteristics such as core of the starting point of the random growth while forming as main burning, et al., Supercond.Sci.Technol.23 (2010) 014015).

About the thick-film of coating repeatedly by the end of tested mistake of in August, 2008, in the full-fledged research group of TFA-MOD method that comprises day USA and Europe, all not report and stably obtained the wire rod that surpasses 100m, this is also considered to because the cause of above-mentioned reason.This be because the problem of residual carbon, the problem of the segregation of metal kind, be repeatedly coated with the characteristic destabilization that Shi You lower floor thermal history causes problem, by the problem of the interface random growth that homogenizing does not cause etc., become reason.

Anti-cracking agent causes chemical reaction in inside, and for the problem of metal ingredient segregation and the problem that superconducting characteristic is reduced as residual carbon composition, Araki is used mainly comprise-(CF ₂) _n-Anti-cracking agent carried out the exploitation (JP4738322B2, US7833941B2) of thick-film method.The method is also while usining as pre-burning in TFA-MOD method, to discharge the Carbon expulsion scheme(T.Araki of the mechanism of carbon, et al., IEEE Trans.on Appl.Supercond., 13, (2003) 2803-2808) be, foundational development technology out.The limit of avoiding burning, TFA-MOD method limit when pre-burning temporarily forms metal oxide, and a part for the bonded oxygen of Y and Ba is substituted by F.The carbon component that reacts irrelevant with these becomes low-boiling material volatilization and is removed.Here it is, and carbon is discharged the main points of mechanism.Equally, in Anti-cracking agent, also not leave the mode of residual carbon, use the organic substance that fluorine ratio is high to carry out thick-film, this is the once coating thick-film technology of Araki.

Once be coated with thick-film technology since Araki etc. is since the world in August, 2008 association delivers, no matter Shi U.S. or all promoted rapidly in Europe.About the once coating thick-film carrying out in the U.S., due to the detailed content of technique report not, so detailed content is indefinite, but likely carried out the thick-film of close content.Once be coated with thick-film technology and compare with being repeatedly coated with thick-film method, there is no the characteristic destabilization as the wire rod due to lamination interface destabilization, in TFA-MOD method, think and need the pre-sinter process of long time treatment also can only once just complete.Therefore, this technology is especially in the time will obtaining the stable film that surpasses 0.5～0.6 μ m, the technology of exploiting one's power.

The thick-film technology that is once coated with of 2006 of Araki has realized at world wide the superconducting film that there is no crackle that coating film forming is 1.3 μ m first, and it is true although little, having obtained superconducting characteristic.But, will be with the superconducting material of this thick-film technology film forming 1.5 μ m or 2.0 μ m sizes time, in order stably to carry out film forming, the special pre-burning condition of known needs.In addition, the film forming that the manufacture of long size wire rod need to be carried out with continuous processing, the coating solution that need to be added with Anti-cracking agent exists long-term and stably.After known a part of Anti-cracking agent mixes with solution sometimes, can not stably exist for a long time, although can film forming when small sample, exist and be not suitable for keeping for a long time the material of the continuous processing of solution.

About not containing the pre-sinter process of Anti-cracking agent, because three kinds of trifluoroacetates decompose at more approaching temperature, so concentrate the crackle causing to produce in order to prevent stress, (T.Araki slowly need to heat up, et al., IEEE Trans.on Appl.Supercond., 13, (2003), 2803-2808).On the other hand, known when adding Anti-cracking agent, when slowly heating up, because CuO carries out germination, so stress is accumulated in inside and easily cracked.

In 2006, carried out at that time partial pressure of oxygen to be fixed as 100% pre-burning, but according to pre-sinter process Anti-cracking agent sometimes meeting burning, the known pre-burning of carrying out might not be got well under 100% oxygen atmosphere.

Accompanying drawing explanation

Fig. 1 means the flow chart of an example of the coating solution of preparing the first execution mode.

Fig. 2 means from the coating solution of the first execution mode and Anti-cracking agent the flow chart of an example of the method for superconductor film forming.

Fig. 3 A, Fig. 3 B are the interpolation CF of embodiment 1 ₂h-(CF ₂) ₃the outward appearance photo of the resulting gel mould of-COOH.

Fig. 4 A-C is the interpolation CF of embodiment 1 ₂h-(CF ₂) ₄-CF ₂the outward appearance photo of the resulting gel mould of H.

Fig. 5 is the interpolation CF of embodiment 1 ₂h-(CF ₂) ₃the section S EM image of the resulting gel mould of-COOH.

Fig. 6 is the interpolation CF of embodiment 1 ₂h-(CF ₂) ₃the TOF-SIMS image of the resulting gel mould of-COOH.

Fig. 7 is the pre-burning curve of embodiment 1 grade.

Fig. 8 is the interpolation CF of embodiment 1 ₂h-(CF ₂) ₄-CF ₂the section S EM image of the resulting gel mould of H.

Fig. 9 is the main burning curve of embodiment 4 grades.

Figure 10 is the interpolation CF of embodiment 5 ₂h-(CF ₂) ₃the cross section tem observation image of the resulting pre-burning film of-COOH.

Figure 11 is the interpolation CF of embodiment 5 ₂h-(CF ₂) ₇the cross section tem observation image of the resulting pre-burning film of-COOH.

Figure 12 is the thick-film that uses Anti-cracking agent to carry out, the illustraton of model before pre-burning.

The figure of the impact that when Figure 13 means pre-burning, partial pressure of oxygen causes for thick-film.

Figure 14 is the EDS distribution map that is once coated with thick film pre-burning film inside of embodiment 7.

Crackle production model when Figure 15 is main burning.

Figure 16 is that the once thickness of coating of embodiment 16 is the cross section TEM image of the superconducting film of 5.2 μ m.

Embodiment

The manufacture method of oxide superconductor of the present invention comprises: dissolve and to comprise the fluorine-containing carboxylate that mixes the trifluoroacetate that is selected from the metal of yttrium and lanthanide series (wherein not comprising cerium, praseodymium, promethium, ruthenium) and barium and copper and obtains, the coating solution that the alcohol that comprises methyl alcohol is solvent is take in preparation, in above-mentioned coating solution, add CF ₂h-(CF ₂) _n-COOH or HOCO-(CF ₂) _m-COOH(n, m are positive integer) as Anti-cracking agent, use is added with the coating solution of above-mentioned Anti-cracking agent, on substrate, form gel mould, the total time that the partial pressure of oxygen of take is the operation below 3%, more than 200 ℃ is the mode below 7 hours, above-mentioned gel mould is carried out to pre-burning, form pre-burning film, above-mentioned pre-burning film is carried out to main burning and oxygen annealing, form the film of oxide superconductor.

Below, with reference to accompanying drawing, for oxide superconductor of the present invention, describe.

The present invention relates to oxide superconducting wire rod and application thereof, the manufacture method of the oxide superconductor particularly using in superconducting power transmission cable, superconducting coil, superconducting magnet, MRI device, magnetic suspension train, SMES etc.

In the present invention, in order effectively to realize stable thick-film, provide following solution.(1) the necessary pre-burning condition of burning that the reason easily cracking in keeping for a long time when the Anti-cracking agent stably existing in coating solution of TFA-MOD method, (2) pre-burning and countermeasure, (3) suppress Anti-cracking agent.

According to the present invention, even under the state that dispense tip or meniscus minister time contact with solution as die coating (die coating) or wound roll material coating (web coating) in continuous processing, also can stably carry out film forming, can provide than Araki first to file (JP4738322B2, US7833941B2) more stably and reproducibility obtain well the method for the thick film that surpasses 1.5 μ m.

(the first execution mode)

The manufacture method of the oxide superconductor of present embodiment comprises: dissolve and to comprise the fluorine-containing carboxylate that mixes the trifluoroacetate that is selected from the metal of yttrium and lanthanide series (wherein not comprising cerium, praseodymium, promethium, ruthenium) and barium and copper and obtains in the mode of 1:2:3 roughly, the coating solution that the alcohol that comprises methyl alcohol is solvent is take in preparation, in coating solution, add CF ₂h-(CF ₂) _n-COOH or HOCO-(CF ₂) _m-COOH(n, m are positive integer) as Anti-cracking agent, use is added with the coating solution of Anti-cracking agent, on substrate, form gel mould, the total time that the partial pressure of oxygen of take is the operation below 3%, more than 200 ℃ is the mode below 7 hours, gel mould is carried out to pre-burning, form pre-burning film, pre-burning film is carried out to main burning and oxygen annealing, form the film of oxide superconductor.

Fig. 1 means the flow chart of an example of the coating solution of preparing present embodiment.

In the manufacture method of present embodiment, first, dissolving comprises that atomic ratio with 1:2:3 roughly mixes the metal that is selected from yttrium and lanthanide series (wherein not comprising cerium, praseodymium, promethium, ruthenium) and barium and copper and the fluorine-containing carboxylate of the trifluoroacetate that obtains, and the coating solution that the alcohol that comprises methyl alcohol is solvent is take in preparation.

Particularly, as shown in Figure 1, prepare metal acetate, for example yttrium, barium, copper acetate (a1) separately.In addition, prepare containing carboxylic acid fluoride (a2).Then, make the metal acetate of preparing be dissolved in (b) in water, with prepare containing carboxylic acid fluoride, mixes and makes it react (c).By resulting solution purification (d), obtain the powder (colloidal sol) or the gel (e) that contain impurity.Afterwards, resulting colloidal sol or gel are dissolved in to (f) in methyl alcohol, make the solution (g) that contains impurity.By resulting solution purification, remove impurity (h), the powder (colloidal sol) that obtains containing solvent or gel are (i).Further, resulting colloidal sol or gel are dissolved in to (j) in methyl alcohol, prepare coating solution (k).

Wherein, " the roughly atomic ratio of 1:2:3 " refers to and is not limited to the situation that atomic ratio is entirely 1:2:3, accept the concept of a little bias.A little bias for example refers to and to be caused by the purity of acetate or the crystallization water yield, when raw material mixes, allows to depart from the concept of 5% left and right from 1:2:3 atomic ratio.In addition, be illustrated in this composition and do not contain for improving the amount such as dopants such as Dy2O3 particles of magnetic field superconducting characteristic.

Expect to contain in fluorine-containing carboxylate 70 % by mole of above trifluoroacetates.Liquid phase reactor in TFA-MOD method when causing distinctive main burn needs fluorinated carboxylic, and the minimum fluorinated carboxylic of carbon number is trifluoroacetic acid.Even while using a part of carbon number to increase by the five fluorine propionic acid of, also can cause that residual carbon increases, carbon component is with CO or CO ₂form at YBa ₂cu ₃o _7-xthe CuO face diffusion of superconductor, superconducting characteristic reduces.Therefore, expectation trifluoroacetic acid is more than 70 % by mole.

In addition, expectation methyl alcohol is solvent more than 80 % by mole.Alcohol be in organic solvent volatility the highest be methyl alcohol.Also can film forming even if mix a small amount of other alcohol, but when when more than 20 % by mole, film forming with burn till after residual carbon composition increase, superconducting characteristic reduction.As long as the solvent beyond methyl alcohol is 20 % by mole and just can be accepted below, but characteristic has the tendency slightly reducing.

Fig. 2 is by the flow chart of an example of the method for superconductor film forming from the coating solution of present embodiment and Anti-cracking agent.

In the manufacture method of present embodiment, in coating solution, add CF ₂h-(CF ₂) _n-COOH or HOCO-(CF ₂) _m-COOH(n, m are positive integer) as Anti-cracking agent, use is added with the coating solution of Anti-cracking agent, on substrate, form gel mould, the total time that the partial pressure of oxygen of take is the operation below 3%, more than 200 ℃ is the mode below 7 hours, gel mould is carried out to pre-burning, form pre-burning film, pre-burning film is carried out to main burning and oxygen annealing, form the film of oxide superconductor.

Particularly, as shown in Figure 2, first, prepare coating solution and the Anti-cracking agent (a) of previously preparation.In the coating solution of preparing, the same Anti-cracking agent of adding preparation, makes the mixing coating solution (b) that has added Anti-cracking agent.Afterwards, by mixing coating solution is for example coated on substrate by die coating method, carry out film forming (c), obtain gel mould (d).Afterwards, resulting gel mould is carried out to once heat treated pre-burning of conduct, decomposing organic matter (e), obtains pre-burning film (f).Further this pre-burning film is carried out to the main burning (g) as secondary heat treatment, afterwards, for example, carry out pure oxygen anneal (h), obtain superconductor (i).

Substrate is for example LaAlO ₃monocrystal substrate, but as long as for forming the substrate of gel mould, be just not limited to this.Both can be for having formed CeO ₂the zirconia of the YSZ(yittrium oxide strengthening in intermediate layer (intermediate layer)) substrate, can be also CeO ₂/ YSZ/Y ₂o ₃the metal tape of film forming.During superconduction film forming, there is not in the intermediate layer of chemical reaction lattice constant suitable, can carry out at an upper portion thereof superconduction film forming yet.

CF is used in Anti-cracking agent ₂h-(CF ₂) _n-COOH or HOCO-(CF ₂) _m-COOH(n, m are positive integer).Particularly, owing to preventing that crackle effect is large, thereby wish n=2～6, m=2～5.

In the Anti-cracking agent of adding, preferably do not react, be all strong acid with trifluoroacetic acid and the perfluorocarboxylic acid of reduced in segregation when mixing.In the Anti-cracking agent of adding, perfluorocarboxylic acid is 75 % by mole when above, prevents that crackle effect from becoming large, so preferably.This is owing to using while not showing highly acid Anti-cracking agent, can be separated in solution with the trifluoroacetate of strong acid, thus can lose the cause that prevents crackle effect.

But, for the perfluorocarboxylic acid without hydrogenation, the opposition side neutralization of carboxyl, carboxyl surrounds metallic element etc. and becomes micellelike, promotes the separation in solution, therefore prevents that crackle effect from reducing.So, as the effective material of Anti-cracking agent, be by chemical formula CF ₂h-(CF ₂) _n-COOH or HOCO-(CF ₂) _mthe material that-COOH records.When by these materials so that it during to be more than 75 % by mole mode in Anti-cracking agent add solution to time, prevents that crackle effect from becoming large and preferably.

As the addition of Anti-cracking agent, with respect to the amount of trifluoroacetate, be that 3～25 atom % are appropriate.When very few, lose and prevent crackle effect, in the time of too much, likely by residual carbon, cause superconducting characteristic to reduce.

From adding Anti-cracking agent till the time that film forming finishes be contemplated to be in the space of management methanol vapor amount, steam vapour amount and be the short time.As long as be 1 hour with interior film forming, just can realize stable film forming.But, when forming 1000m band, with the film forming speed of 1m/ minute, need the time of 16 hours 40 minutes.Therefore,, after solution mixes, need the Anti-cracking agent that solution certain hour can be not deteriorated.

The mixing coating solution of the Anti-cracking agent of employing present embodiment is very stable.Add after Anti-cracking agent to the time that forms gel mould be 60 minutes above oneself needless to say, even also can carry out good film forming above at 24 hours.That is, in Fig. 2 from mix coating solution make (b Fig. 2) to the time of film forming (c in Fig. 2) be 60 minutes above oneself needless to say, even if be, within 24 hours, also can stablize film forming above.

Particularly, by application carbon number few Anti-cracking agent, even add after Anti-cracking agent to the time that forms gel mould be 7 days above and then be more than 14 days, also can carry out good film forming.

In present embodiment, take total time of 200 ℃ of above operations carries out pre-burning as the mode below 7 hours.That is, when pre-burning, 200 ℃ of above times that keep, add up to below 7 hours.

The temperature that should stipulate is the temperature that trifluoroacetic acid copper decomposes, CuO nano microcrystalline forms.This temperature is more accurately that the possibility of 210-220 ℃ is high, but detailed mechanism is still not clear.This retention time more than temperature can add up to below 6 hours, but known today be can carry out good film forming below by 200 ℃ of above maintenance temperature being made as to 7 hours.

In the pre-burning film of the thick film that adds Anti-cracking agent and obtain, there is the space of being caused by Anti-cracking agent.There is bridge portion in the surrounding in this space, but has a large amount of CuO nano microcrystallines in this bridge portion, the known growth of following temperature hold-time and germination, and stress increases.It is a certain amount of when above that this stress reaches, and bridge is destroyed, thereby form crackle.Therefore,, during by the pre-burning film film forming of thick film, it is the short time as far as possible that the temperature after expectation CuO forms keeps.

On the other hand, 200 ℃ of needed minimum times of above heating, be how much to be still not clear at present.In TFA-MOD method, need to decompose trifluoroacetate and generate oxide, a part is become to fluoride.But this is because when having added Anti-cracking agent, also can be caused and fluoridize by this chemical substance, thereby react in the short time cause finishing.

At least in the situation that there is no Anti-cracking agent, the pre-burning (JP4738322B2, US7833941B2) of minimum needs about 7 hours, but in the situation that having used perfluorocarboxylic acid, must be made as the pre-burning of maximum 7 hours.Like this, in being mixed with the solution of Anti-cracking agent, optimum pre-sinter process can significantly change.

In addition, in the present embodiment, take partial pressure of oxygen as implementing pre-burning below 3%.For better film forming, expectation partial pressure of oxygen is below 1%, and more expectation is below 0.3%.Known to preventing that violent burning of Anti-cracking agent suppressed the generation of crackle under hypoxemia.

Because Anti-cracking agent is decomposed, so need oxygen when pre-burning.But the lower limit of this oxygen amount is how much to be still not clear at present.The oxygen of take can obtain thick film to be once coated with as 0.1%, 0.01%, 0.001% heat treatment of carrying out.The oxygen of take also can access thick film as 0.0001% heat treatment of carrying out, but while realizing with its following partial pressure of oxygen, in gas cylinder, residual oxygen composition is 0.2ppm left and right, is experimentally very difficult.

Wherein, also known 30% or 10% time crackle produce and become quite violent, the known thick film that is difficult to obtain 1.5 μ m left and right with this partial pressure of oxygen amount.At present knownly heat-treat in the thick film obtaining as 1% take oxygen, even if residual clearance also can access the superconducting film of the orientation of 5.2 μ m.In this film, confirmed that the face orientation of perovskite structure is consistent with substrate orientation till near surface, realized the growth of TFA-MOD method.

Above, according to present embodiment, the heat-treat condition when oxygen concentration when simultaneously realizing selection, the pre-burning of Anti-cracking agent, pre-burning, provides the method for the pre-burning film that stably obtains flawless thick film.By this technology, coating just can realize the film that thickness is 5.2 μ m and flawless oxide superconductor at least one times.

(the second execution mode)

The manufacture method of the oxide superconductor of present embodiment comprises: dissolve to comprise in the mode of 1:2:3 roughly and mix the metal that is selected from yttrium and lanthanide series (wherein not comprising cerium, praseodymium, promethium, ruthenium) and barium and copper and the fluorine-containing carboxylate of the trifluoroacetate that obtains, the coating solution that the alcohol that comprises methyl alcohol is solvent is take in preparation, in coating solution, add CF ₂h-(CF ₂) _n-COOH or HOCO-(CF ₂) _m-COOH(n, m are positive integer) in material after being replaced by least more than one Y, La, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Ba, Cu of carboxylic acid group's (COOH) H as Anti-cracking agent, use is added with the coating solution of Anti-cracking agent, on substrate, form gel mould, the total time that the partial pressure of oxygen of take is the operation below 3%, more than 200 ℃ is the mode below 7 hours, gel mould is carried out to pre-burning, form pre-burning film, pre-burning film is carried out to main burning and oxygen annealing, form the film of oxide superconductor.

In the present embodiment, except comprising CF in Anti-cracking agent ₂h-(CF ₂) _n-COOH or HOCO-(CF ₂) _m-COOH(n, m are positive integer) in material after being replaced by least more than one Y, La, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Ba, Cu of carboxylic acid group's (COOH) H beyond, same with the first execution mode.Therefore,, for the content with the first execution mode repetition, omit and describe.

In the present embodiment, in Anti-cracking agent, use CF ₂h-(CF ₂) _n-COOH or HOCO-(CF ₂) _m-COOH(n, m are positive integer) in material after being replaced by least more than one Y, La, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Ba, Cu of carboxylic acid group's (COOH) H.This material is CF ₂h-(CF ₂) _n-COOH or HOCO-(CF ₂) _m-COOH(n, m are positive integer) in the material of carboxylic acid group's (COOH) the H metallic element that is configured superconductor after replacing.This material is also brought into play the function of Anti-cracking agent.

This material can be both for example HOCO-(CF ₂) ₂cuOCO-(the CF that the hydrogen of-COOH is replaced by copper ₂) ₂-COOCu can be also CF ₂h-(CF ₂) ₃the CF that the hydrogen of-COOH is replaced by copper ₂h-(CF ₂) ₃-COOCu.

The in the situation that hydrogen amount being extremely few in Anti-cracking agent, likely losing and prevent crackle effect.With respect to this, the Anti-cracking agent not replaced by metallic element by adding appropriate hydrogen, can avoid.

For example,, by CuOCO-(CF ₂) ₂medium mole of ground of-COOCu adds HOCO-(CF ₂) ₂-COOH, can be made as 80% by fluorine ratio, thereby can improve the effect that prevents crackle.Now, prediction, when this mixes, has formed HOCO-(CF ₂) ₂-COOCu.

Therefore, in the present embodiment, in order to reduce fluorine ratio or in order to improve hydrogen ratio, to be desirably in the further CF of interpolation in coating solution ₂h-(CF ₂) _n-COOH or HOCO-(CF ₂) _m-COOH is as Anti-cracking agent.

In the present embodiment, also same with the first execution mode, stably obtained the pre-burning film of flawless thick film.And, can realize the thick film of flawless oxide superconductor.

Embodiment

(embodiment 1)

By Y (OCOCH ₃) ₃, Ba (OCOCH ₃) ₂, Cu (OCOCH ₃) ₂the powder of each hydrate be dissolved in respectively in ion exchange water, respectively with the CF that reacts equimolar amounts ₃cOOH mixes and stirs, and with metal ion mol ratio, 1:2:3 mixes, and obtains mixed solution.Resulting mixed solution is added in eggplant type flask, carries out reaction and the purifying of 12 hours in rotary evaporator under decompression, obtains gel or the colloidal sol of semi-transparent blue.

Resulting gel or colloidal sol are added to (f of Fig. 1) dissolving completely in the methyl alcohol that is equivalent to its approximately 100 times of weight, this solution is carried out to reaction and the purifying of 12 hours again in rotary evaporator under decompression, can obtain gel or the colloidal sol of semi-transparent blue.

Resulting gel or colloidal sol are dissolved in methyl alcohol (j of Fig. 1), by using volumetric flask to dilute, in metal ion, convert and obtain the coating solution 1Cs-base(embodiment 1 of 1.86M, coating solution material).

Using having added with respect to trifluoroacetate solute as Anti-cracking agent in coating solution 1Cs-base, be the CF of 15 % by weight ₂h (CF ₂) ₃the solution of COOH is as mixing coating solution 1Cs-A.Using having added with respect to trifluoroacetate solute as Anti-cracking agent in coating solution 1Cs-base, be the CF of 15 % by weight ₂h (CF ₂) ₄cF ₂the solution of H is as mixing coating solution 1Cs-B.

Mixing coating solution 1Cs-A is added to 100cc beaker and is about 30mm to reach the depth of water, the orientation LaAlO that two sides is ground ₃monocrystal substrate is immersed in above-mentioned solution, at temperature, be to flood 1 minute under 25 ℃, the relative humidity environment that is 30-45RH%, then with the speed of 70mm/ second, carry out pulling out of monocrystalline, obtained respectively 6 clotting glued membrane 1Cs-A-Gf-01 (gel mould sample No.01), 1Cs-A-Gf-02,1Cs-A-Gf-03,1Cs-A-Gf-04,1Cs-A-Gf-05,1Cs-A-Gf-06.From 1Cs-B, 1Cs-B-Gf-01,1Cs-B-Gf-02,1Cs-B-Gf-03,1Cs-B-Gf-04,1Cs-B-Gf-05,1Cs-B-Gf-06 have also been obtained respectively equally.

In addition, all gel moulds are in two sides film forming after just film forming, but a face is just being wiped after film forming.This is wiped in drying regime and carries out, and the therefore gel mould of residual lower striated, if see in the enlarged photograph of gel mould that striated is because this is wiped and causes.The calculated value that carries out the gel mould of film forming under this condition is 10 μ m, and the calculated value after pre-burning and main burning is 2.0 μ m, 1.0 μ m.

The moisture absorption of gel mould is understood deteriorated very by force, therefore 1Cs-A-Gf-01, the 1Cs-A-Gf-02,1Cs-B-Gf-01, the 1Cs-B-Gf-02 that as gel mould, have carried out observing are being stopped to the teflon of moisture (registered trade mark) is in special container, respectively to put into two, by abundant dry replacement of oxygen for inner gas, then to put into gel mould, then in order stopping from outside moisture absorption, to be made as at once the state closing the lid.It is for the convenience on observing that gel mould is fixed on to plastic containers with two-sided tape.

Fig. 3 A, Fig. 3 B are used CF in Anti-cracking agent ₂h (CF ₂) ₃the thickness that COOH has carried out thick-film is the outward appearance photo of the gel mould of 10 μ m.Fig. 3 A is that after firm film forming, (in 5 minutes), Fig. 3 B are the outward appearance photos of 96 hours after film forming.Fig. 3 A and Fig. 3 B have been formed uniformly nattier blue gel mould.

Fig. 4 A-C is used CF in Anti-cracking agent ₂h (CF ₂) ₄cF ₂the thickness that H has carried out thick-film is the outward appearance photo of the gel mould of 10 μ m.Fig. 4 A is that after firm film forming, (in 5 minutes), Fig. 4 B are that after film forming, 48 hours, Fig. 4 C are the outward appearances of 96 hours after film forming.Fig. 4 A is formed uniformly nattier blue gel mould at whole face, and in Fig. 4 B, it condenses upon central portion, and in Fig. 4 C, it further condenses.

For the photo after firm film forming, in Fig. 3 A, represent 1Cs-A-Gf-01,1Cs-A-Gf-02, in Fig. 4 A, represent 1Cs-B-Gf-01,1Cs-B-Gf-02.Although see through container, can slightly hazily see, known whole gel mould all adequate relief becomes nattier blue film.

The environment that gel mould is placed is 25 ℃.Inner humidity remains on the state of 0-5%.1Cs-B-Gf-01,1Cs-B-Gf-02 are in the moment of having passed through 48 hours, and two have all been observed the trend of shrinking, have become Fig. 4 B such.Fig. 4 A left side is 1Cs-B-Gf-01.And then it is such after 96 hours, to become Fig. 4 C.On the other hand, 1Cs-A-Gf-01,1Cs-A-Gf-02 are after 96 hours in Fig. 3 B, and two all almost do not change in appearance, are keeping nattier blue gel mould, after 240 hours, do not change yet.

Fig. 5 is used CF in Anti-cracking agent ₂h (CF ₂) ₃the thickness that COOH has carried out thick-film is the section S EM image of the gel mould of 10 μ m.Gel mould 1Cs-A-Gf-01(Fig. 3 A is left) be not exposed to the result that there is the atmosphere of humidity and carry out SEM observation as shown in Figure 5.

Known gel mould is the thickness with essentially identical 10 about μ m of calculated value.In addition, although at surface observation to the layer that is by volume the drying regime of 3% left and right, this is considered to the cause of preserving under dry atmosphere due to for a long time, the state that other parts of gel mould are homogeneous.

Fig. 6 is the TOF-SIMS image of Fig. 5.The result of analyzing gel mould 1Cs-A-Gf-01 with TOF-SIMS is Fig. 6.

Y ⁺, Ba ⁺, Cu ⁺in composition, do not observe segregation completely.From the result of Fig. 6, due to the state for before pre-burning, thus also contain carbon component, but this composition is also mixed in heterogeneity.Known by using CF ₂h (CF ₂) ₃cOOH has formed the gel mould of homogeneous as the thick-film of Anti-cracking agent.

Fig. 7 is the pre-burning curve of TFA-MOD method.The pre-burning curve that remaining gel mould 1Cs-A-Gf-03,1Cs-A-Gf-04,1Cs-A-Gf-05,1Cs-A-Gf-06,1Cs-B-Gf-03,1Cs-B-Gf-04,1Cs-B-Gf-05,1Cs-B-Gf-06 record according to Fig. 7 is respectively heat-treated.In the curve that Fig. 7 records, according to the heat treatment time of 200-250 ℃ being made as to 9 hours 43 minutes, by 250-300 ℃ be made as 1 hour 40 minutes, by 300-400 ℃ of curve that is made as 0 hour 20 minutes, heat-treat.

1Cs-A-Gf-03,1Cs-A-Gf-04,1Cs-B-Gf-03,1Cs-B-Gf-04 carry out pre-burning in 10% oxygen, and 1Cs-A-Gf-05,1Cs-A-Gf-06,1Cs-B-Gf-05,1Cs-B-Gf-06 carry out pre-burning in 100% oxygen.Consequently, obtain flawless pre-burning film only for 1Cs-A-Gf-03,1Cs-A-Gf-04.

As Anti-cracking agent, CF ₂h (CF ₂) ₃cOOH and CF ₂h (CF ₂) ₄cF ₂the molecular weight of H is basic identical.In addition, fluorine ratio (fluorine atom is with respect to the ratio of fluorine atom+hydrogen atom) does not have large difference yet.Whether what can be used as that both difference considers is can coexist with trifluoroacetate is stable in solution.

Trifluoroacetic acid in its structure, electronics exist probability from carboxy moiety to CF ₃-side shifting, hydrogen, the metallic element of bonding easily depart from.The estimation pH of trifluoroacetic acid is-0.6 left and right, although show great acidity for organic substance.

Can think as Anti-cracking agent, CF ₂h (CF ₂) ₃cOOH has identical structure, thus strong acid can coexist each other, but CF ₂h (CF ₂) ₄cF ₂h is owing to not having this structure, so separated in solution.Therefore, can think in gel mould, also maintain unsure state, along with the time changes, film is inner separated, becomes the such result of Fig. 4 A-C.

Sometimes in coating solution, mix Anti-cracking agent, then in the short time, carry out film forming, obtain gel mould, but in continuous processing, in coating solution, add after Anti-cracking agent during till film forming and passed through certain hour.Known now CF ₂h (CF ₂) ₄cF ₂h is not suitable as Anti-cracking agent.

In order to study CF ₂h (CF ₂) ₄cF ₂h is not suitable as the reason of Anti-cracking agent, studies it and has used CF ₂h (CF ₂) ₃the difference of gel mould during COOH.1Cs-A-Gf-07, the 1Cs-A-Gf-08 of 1Cs-A-Gf-01 reproduced in making, in order not occur deteriorated, puts into the bottle of dry atmosphere, for mobile or deteriorated not carrying out, in refrigerator (approximately 8 ℃), gel mould only preserved 24 hours, analyzes.Before gel mould is analyzed, 1Cs-A-Gf-08 is preserved in refrigerator 7 days.Known now gel mould is not moving and be maintained as Fig. 4 A-C not.

Fig. 8 is used CF in Anti-cracking agent ₂h (CF ₂) ₄cF ₂the thickness that H carries out thick-film is the section S EM image of the gel mould of 10 μ m.For 1Cs-A-Gf-07, do not preserve and the section S EM that carries out immediately gel mould observes.Its result is illustrated in Fig. 8.

From with Fig. 5 relatively, for the gel mould of Fig. 8, although carried out between should storage life short, deteriorated few stored refrigeratedly, from top to central portion, still observe that some are rotten.This causes because of blanketing gas (pure oxygen) owing to preserving, although thereby owing to wanting merely cohesion but the positive top of substrate because substrate and gel have adhered to by Stress Release cohesion, only go bad on top, be still not clear at present.Even known outward appearance seems complete film, when using, not during based on Anti-cracking agent of the present invention, in gel mould inside, also can there is segregation.

(embodiment 2)

By Y (OCOCH ₃) ₃, Ba (OCOCH ₃) ₂, Cu (OCOCH ₃) ₂the powder of each hydrate be dissolved in respectively in ion exchange water, respectively with the CF that reacts equimolar amounts ₃cOOH mixes and stirs, and with metal ion mol ratio, 1:2:3 mixes, and obtains thus mixed solution.Resulting mixed solution adds in eggplant type flask, carries out reaction in 12 hours and purifying in rotary evaporator under decompression, obtains gel or the colloidal sol of semi-transparent blue.

Resulting gel or colloidal sol are added to (f of Fig. 1) dissolving completely in the methyl alcohol that is equivalent to its approximately 100 times of weight, this solution is carried out to reaction and the purifying of 12 hours again in rotary evaporator under decompression, obtain gel or the colloidal sol of semi-transparent blue.

Resulting gel or colloidal sol are dissolved in methyl alcohol (j of Fig. 1), by using volumetric flask to dilute, obtain the coating solution 2Cs-base in metal ion conversion 1.86M.

In coating solution 2Cs-base, adding with respect to trifluoroacetate solute is that the following material of 15 % by weight is as Anti-cracking agent.To in 2Cs-base, add HOCO (CF ₂) ₂cOOH, HOCO (CF ₂) ₃cOOH, HOCO (CF ₂) ₄cOOH, HOCO (CF ₂) ₅cOOH, HOCO (CF ₂) ₆cOOH, HOCO (CF ₂) ₇cOOH, HOCO (CF ₂) ₈cOOH, HOCO (CF ₂) ₁₀the coating solution of COOH is respectively as 2Cs-PFDA-C04(embodiment 2, coating solution, perfluor binary acid, carbon number is 4), 2Cs-PFDA-C05,2Cs-PFDA-C06,2Cs-PFDA-C07,2Cs-PFDA-C08,2Cs-PFDA-C09,2Cs-PFDA-C10,2Cs-PFDA-C12.

To in 2Cs-base, add HOCO (CF ₂) O (CF ₂) ₂oCF ₂cOOH, HOCO (CF ₂) O (CF ₂) O (CF ₂) ₂oCF ₂the mixing coating solution of COOH is respectively as 2Cs-PFO-C06(perfluor-3,6-dioxa octane-1,8-diacid), 2Cs-PFO-C08.

To in 2Cs-base, add CF ₂h (CF ₂) ₂cF ₂h, CF ₂h (CF ₂) ₃cF ₂h, CF ₂h (CF ₂) ₄cF ₂h, CF ₂h (CF ₂) ₅cF ₂h, CF ₂h (CF ₂) ₆cF ₂h, CF ₂h (CF ₂) ₈cF ₂the mixing coating solution of H is respectively as 2Cs-PFA-C04(perfluoro alkane), 2Cs-PFA-C05,2Cs-PFA-C06,2Cs-PFA-C07,2Cs-PFA-C08,2Cs-PFA-C10.

To in 2Cs-base, add CF ₃(CF ₂) ₂cOOH, CF ₃(CF ₂) ₃cOOH, CF ₃(CF ₂) ₄cOOH, CF ₃(CF ₂) ₅cOOH, CF ₃(CF ₂) ₆cOOH, CF ₃(CF ₂) ₇cOOH, CF ₃(CF ₂) ₈cOOH, CF ₃(CF ₂) ₉the mixing coating solution of COOH is respectively as 2Cs-PFC-C04(perfluorocarboxylic acid), 2Cs-PFC-C05,2Cs-PFC-C06,2Cs-PFC-C07,2Cs-PFC-C08,2Cs-PFC-C09,2Cs-PFC-C10,2Cs-PFC-C11.

To in 2Cs-base, add CF ₂h (CF ₂) ₂cOOH, CF ₂h (CF ₂) ₃cOOH, CF ₂h (CF ₂) ₄cOOH, CF ₂h (CF ₂) ₅cOOH, CF ₂h (CF ₂) ₆cOOH, CF ₂h (CF ₂) ₇cOOH, CF ₂h (CF ₂) ₈cOOH, CF ₂h (CF ₂) ₉the mixing coating solution of COOH is respectively as 2Cs-HPFC-C04(5H-perfluorocarboxylic acid), 2Cs-HPFC-C05,2Cs-HPFC-C06,2Cs-HPFC-C07,2Cs-HPFC-C08,2Cs-HPFC-C09,2Cs-HPFC-C10,2Cs-HPFC-C11.

The whole mixing coating solution that has added the above-mentioned record of Anti-cracking agent is added respectively in 100cc beaker and makes the depth of water be about 30mm, the orientation LaAlO that two sides is ground ₃monocrystal substrate is immersed in above-mentioned solution, at temperature, is in container, to mix 60 minutes under 25 ℃, the relative humidity environment that is 30-45RH%, then with the speed of pulling out of 70mm/ second, carries out pulling out of monocrystalline, obtains respectively 1 clotting glued membrane.For example, will be made as 2Gf-PFDA-C04 from mixing the resulting gel mould of coating solution 2Cs-PFDA-C04.

The pre-burning curve that whole gel moulds are recorded according to Fig. 7 is heat-treated.In the curve that Fig. 7 records, according to the heat treatment time of 200-250 ℃ being made as to 9 hours 43 minutes, 250-300 ℃ is made as to 1 hour 40 minutes, 300-400 ℃ of curve that is made as 0 hour 20 minutes heat-treated.Oxygen concentration is 10%, and humidification is 4.2%.For example, will be made as 2Cf-PFDA-C04 from the resulting pre-burning film of gel mould 2Gf-PFDA-C04.

At 2Cf-PFO-C06, 2Cf-PFO-C08, 2Cf-PFA-C04, 2Cf-PFA-C05, 2Cf-PFA-C06, 2Cf-PFA-C07, 2Cf-PFA-C08, 2Cf-PFA-C10, 2Cf-PFC-C04, 2Cf-PFC-C05, 2Cf-PFC-C06, 2Cf-PFC-C07, 2Cf-PFC-C08, 2Cf-PFC-C09, 2Cf-PFC-C10, in 2Cf-PFC-C11, confirmed crackle, at 2Cf-PFDA-C04, 2Cf-PFDA-C05, 2Cf-PFDA-C06, 2Cf-PFDA-C07, 2Cf-PFDA-C08, 2Cf-PFDA-C09, 2Cf-PFDA-C10, 2Cf-PFDA-C12, 2Cf-HPFC-C04, 2Cf-HPFC-C05, 2Cf-HPFC-C06, 2Cf-HPFC-C07, 2Cf-HPFC-C08, 2Cf-HPFC-C09, 2Cf-HPFC-C10, in 2Cf-HPFC-C11, do not crack.

Inventor's the film forming when first to file (JP4738322B2, US7833941B2) is all just being carried out film forming after adding Anti-cracking agent in coating solution, confirmed and prevented crackle effect, but considered continuous film forming specifically and reserved the time of repose of 60 minutes.Can think separation etc. occurred in solution inside with this time.

CF ₂h (CF ₂) ₂cF ₂h, CF ₂h (CF ₂) ₃cF ₂h, CF ₂h (CF ₂) ₄cF ₂h, CF ₂h (CF ₂) ₅cF ₂h, CF ₂h (CF ₂) ₆cF ₂h, CF ₂h (CF ₂) ₈cF ₂h in molecular structure, the hydrogen positively charged at both ends, near the fluorine band negative charging it.Therefore,, although should be able to expect the hydrogen bond that hydrogenation perfluorocarboxylic acid is such, do not confirm and prevent crackle effect.

These materials are not owing to having straight chain and the carboxylic acid group who is fluorinated, so do not have the character as strong acid.Therefore, also can be separated even mix with trifluoroacetate, it also can be separated with the material that does not prevent crackle effect.In order playing consistently, to prevent crackle effect, need to have as the straight chain being fluorinated and the carboxyl that show the structure of strong acid simultaneously.

HOCO (CF ₂) O (CF ₂) ₂oCF ₂cOOH, HOCO (CF ₂) O (CF ₂) O (CF ₂) ₂oCF ₂cOOH is owing to having straight chain and the carboxylic acid group who is fluorinated, thus can expect to mix equably with trifluoroacetate, but consider from experimental result, produced quite severe crackle, split into powdery.

In the straight chain of this material, fluorine and oxygen mix existence, thereby there are differences in electronegativity.Can think that when pre-burning this part is subject in comfortable trifluoroacetate the attack with the slaine of positive electricity, break as straight chain, lose the crackle ability that prevents.Therefore, in order bringing into play, to prevent crackle effect, can to think that not wishing is the structure that accompanies oxygen in straight chain, but wish to have continuously the structure of carbon in straight chain.

CF ₃(CF ₂) ₂cOOH, CF ₃(CF ₂) ₃cOOH, CF ₃(CF ₂) ₄cOOH, CF ₃(CF ₂) ₅cOOH, CF ₃(CF ₂) ₆cOOH, CF ₃(CF ₂) ₇cOOH, CF ₃(CF ₂) ₈cOOH, CF ₃(CF ₂) ₉although COOH meets above-mentioned two conditions, has produced crackle.This be because, although from carboxylic acid group's hydrogen, reduced electronics there is probability and positively charged, electronegative is near fluorine carboxylic acid group, the straight chain of the antipode in carboxylic acid group becomes electric neutrality.

Therefore, can think that Anti-cracking agent surrounds electronegative element as the micella of soap, thereby lost, prevent crackle effect.Particularly, this experiment of standing 60 minutes can think that its effect becomes large.In addition, the reason based on same, can infer that the material that end is hydrogenated has the crackle of preventing effect.

From the result of embodiment 2, the material demand that prevents crackle effect of playing stably meets the full terms shown in the material of above-mentioned three systems that produced crackle.This material only has two systems.For CHF ₂-(CF ₂) _n-COOH and HOCO-(CF ₂) _m-COOH.

(embodiment 3)

By Y (OCOCH ₃) ₃, Ba (OCOCH ₃) ₂, Cu (OCOCH ₃) ₂the powder of each hydrate be dissolved in respectively in ion exchange water, respectively with the CF that reacts equimolar amounts ₃cOOH mixes and stirs, and with metal ion mol ratio, 1:2:3 mixes, and obtains thus mixed solution.Resulting mixed solution is added in eggplant type flask, in rotary evaporator, under decompression, carry out reaction and the purifying of 12 hours, obtain gel or the colloidal sol of semi-transparent blue.

Resulting gel or colloidal sol are added in the methyl alcohol that is equivalent to its approximately 100 times of weight to (f of Fig. 1) and dissolves completely, when this solution is carried out to the reaction of 12 hours and purifying again in rotary evaporator under decompression, obtain gel or the colloidal sol of semi-transparent blue.

Resulting gel or colloidal sol are dissolved in methyl alcohol (j of Fig. 1), by using volumetric flask, dilute, and obtain the coating solution 3Cs-base in metal ion conversion 1.86M.

In coating solution 3Cs-base as Anti-cracking agent to add with respect to trifluoroacetate solute be the following material of 15 % by weight.To in 3Cs-base, add HOCO (CF ₂) ₂cOOH, HOCO (CF ₂) ₃cOOH, HOCO (CF ₂) ₄cOOH, HOCO (CF ₂) ₅cOOH, HOCO (CF ₂) ₆cOOH, HOCO (CF ₂) ₇cOOH, HOCO (CF ₂) ₈cOOH, HOCO (CF ₂) ₁₀the mixing coating solution of COOH is respectively as 3Cs-PFDA-C04(embodiment 2, coating solution, perfluor binary acid, carbon number is 4), 3Cs-PFDA-C05,3Cs-PFDA-C06,3Cs-PFDA-C07,3Cs-PFDA-C08,3Cs-PFDA-C09,3Cs-PFDA-C10,3Cs-PFDA-C12.

To in 3Cs-base, add CHF ₂(CF ₂) ₂cOOH, CHF ₂(CF ₂) ₃cOOH, CHF ₂(CF ₂) ₄cOOH, CHF ₂(CF ₂) ₅cOOH, CHF ₂(CF ₂) ₆cOOH, CHF ₂(CF ₂) ₇cOOH, CHF ₂(CF ₂) ₈cOOH, CHF ₂(CF ₂) ₉the mixing coating solution of COOH is respectively as 3Cs-HPFC-C04(5H-perfluorocarboxylic acid), 3Cs-HPFC-C05,3Cs-HPFC-C06,3Cs-HPFC-C07,3Cs-HPFC-C08,3Cs-HPFC-C09,3Cs-HPFC-C10,3Cs-HPFC-C11.

The whole coating solutions that are added with the above-mentioned record of Anti-cracking agent are joined respectively in 100cc beaker and make the depth of water be about 30mm, the orientation LaAlO that two sides is ground ₃monocrystal substrate is immersed in above-mentioned solution, at temperature, be in solution, to mix 3 hours, 6 hours, 1 day, 3 days, 7 days, 14 days under 25 ℃, the relative humidity environment that is 30-45RH%, then with the speed of pulling out of 70mm/ second, carry out pulling out of monocrystalline, obtain respectively 1 clotting glued membrane.

The pre-burning curve that resulting gel mould is recorded according to Fig. 7 is heat-treated.In the curve that Fig. 7 records, according to the heat treatment time of 200-250 ℃ being made as to 9 hours 43 minutes, 250-300 ℃ is made as to 1 hour 40 minutes, 300-400 ℃ of curve that is made as 0 hour 20 minutes heat-treated.Oxygen concentration is 10%, and humidification is 4.2%.

For example use solution 3Cs-PFDA-C04, film forming after solution mixes latter 3 hours and 1 day, by resulting pre-burning film be denoted as respectively 3Cf-PFDA-C04-3 hour here, 3Cf-PFDA-C04-1 days.Study the surface state of resulting pre-burning film, result is learnt in 3Cf-PFDA-C12-7 days, 3Cf-PFDA-C09-14 days, 3Cf-PFDA-C10-14 days, 3Cf-PFDA-C12-14 days, 3Cf-HPFC-C10-7 days, 3Cf-HPFC-C11-7 days, 3Cf-HPFC-C08-14 days, 3Cf-HPFC-C09-14 days, 3Cf-HPFC-C10-14 days, 3Cf-HPFC-C11-14 days and has been produced crackle.

Known when keeping being for a long time mixed with the solution of Anti-cracking agent of long carbochain, there is the trend easily cracking.But these Anti-cracking agent of known interpolation, carry out film forming thereby can stably maintain solution a couple of days.

(embodiment 4)

By Y (OCOCH ₃) ₃, Ba (OCOCH ₃) ₂, Cu (OCOCH ₃) ₂the powder of each hydrate be dissolved in respectively in ion exchange water, respectively with the CF that reacts equimolar amounts ₃cOOH mixes and stirs, with metal ion mol ratio 1:2:3, mixes, and obtains thus mixed solution.Resulting mixed solution is added in eggplant type flask, in rotary evaporator, under decompression, carry out reaction and the purifying of 12 hours, obtain gel or the colloidal sol of semi-transparent blue.

Resulting gel or colloidal sol are added in the methyl alcohol that is equivalent to its approximately 100 times of weight to (f of Fig. 1) and dissolves completely, when this solution is carried out to the reaction of 12 hours and purifying again in rotary evaporator under decompression, obtain gel or the colloidal sol of semi-transparent blue.Resulting gel or colloidal sol are dissolved in methyl alcohol (j of Fig. 1), by using volumetric flask, dilute, and obtain the coating solution 4Cs-base in metal ion conversion 1.86M.

In coating solution 4Cs-base as Anti-cracking agent to add with respect to trifluoroacetate solute be the following material of 15 % by weight.To in 4Cs-base, add HOCO (CF ₂) ₂cOOH, HOCO (CF ₂) ₃cOOH, HOCO (CF ₂) ₄cOOH, HOCO (CF ₂) ₅cOOH, HOCO (CF ₂) ₆cOOH, HOCO (CF ₂) ₇cOOH, HOCO (CF ₂) ₈cOOH, HOCO (CF ₂) ₁₀the mixing coating solution of COOH is respectively as 4Cs-PFDA-C04,4Cs-PFDA-C05,4Cs-PFDA-C06,4Cs-PFDA-C07,4Cs-PFDA-C08,4Cs-PFDA-C09,4Cs-PFDA-C10,4Cs-PFDA-C12.

To in 4Cs-base, add CHF ₂(CF ₂) ₂cOOH, CHF ₂(CF ₂) ₃cOOH, CHF ₂(CF ₂) ₄cOOH, CHF ₂(CF ₂) ₅cOOH, CHF ₂(CF ₂) ₆cOOH, CHF ₂(CF ₂) ₇cOOH, CHF ₂(CF ₂) ₈cOOH, CHF ₂(CF ₂) ₉the mixing coating solution of COOH is made as respectively 4Cs-HPFC-C04,4Cs-HPFC-C05,4Cs-HPFC-C06,4Cs-HPFC-C07,4Cs-HPFC-C08,4Cs-HPFC-C09,4Cs-HPFC-C10,4Cs-HPFC-C11.

The whole coating solutions that are added with the above-mentioned record of Anti-cracking agent are added respectively in 100cc beaker, make the depth of water be about 30mm, the orientation LaAlO that two sides is ground ₃monocrystal substrate is immersed in above-mentioned solution, at temperature, is in solution, to mix two hours under 25 ℃, the relative humidity environment that is 30-45RH%, then with the speed of pulling out of 70mm/ second, carries out pulling out of monocrystalline, obtains respectively 1 clotting glued membrane.

The pre-burning curve that resulting gel mould is recorded according to Fig. 7 is heat-treated.In the curve that Fig. 7 records, according to the heat treatment time of 200-250 ℃ being made as to 9 hours 43 minutes, 250-300 ℃ is made as to 1 hour 40 minutes, 300-400 ℃ of curve that is made as 0 hour 20 minutes heat-treated.Oxygen concentration is 10%, and humidification is 4.2%.For example, the resulting pre-burning film of use solution 4Cs-PFDA-C04 is denoted as to 4Cf-PFDA-C04 here.

Fig. 9 is the main burning curve of TFA-MOD method.Whole pre-burning films is burnt till according to the main burning curve shown in Fig. 9.In the mixing argon gas of the oxygen 1000ppm that is 4.2% at humidification, at 800 ℃, keep 4 hours, carry out main burning, then carry out oxygen annealing from 525 ℃, obtain respectively superconductor.

Pre-burning film 4Cf-PFDA-C04 is carried out to superconducting film that the annealing of main burning and oxygen obtains to be designated as 4Ff-PFDA-C04(and to burn till film).In this test, at LaAlO ₃the thick film film forming of the 1 μ m level of carrying out on monocrystal substrate, although the problem of the known a/b of existence axle orientation grain and have the characteristic 1MA/cm that only risen ²the problem of (77K, 0T) left and right, but differentiate because the characteristic causing because of residual carbon reduces easily, so carried out this test.

Superconducting characteristic is by adopting the mensuration of actinobolia to carry out.The method is that the signal that applies magnetic field in liquid nitrogen, send when destroyed with complete diamagnetism is inferred critical current density.Table 1 represents this result.

Table 1

Test number	Anti-cracking agent	J _cValue (MA/cm ²，77K，0T)
			4Ff-PFDA-C04	HOCO(CF ₂) ₂COOH	1.2
4Ff-PFDA-C05	HOCO(CF ₂) ₃COOH	1.1
			4Ff-PFDA-C06	HOCO(CF ₂) ₄COOH	1.3
4Ff-PFDA-C07	HOCO(CF ₂) ₅COOH	1.1
			4Ff-PFDA-C08	HOCO(CF ₂) ₆COOH	0.8
4Ff-PFDA-C09	HOCO(CF ₂) ₇COOH	0.6
			4Ff-PFDA-C10	HOCO(CF ₂) ₈COOH	0.3
4Ff-PFDA-C12	HOCO(CF ₂) ₁₀COOH	0.4
			4Ff-HPFC-C04	CHF ₂(CF ₂) ₂COOH	1.2
4Ff-HPFC-C05	CHF ₂(CF ₂) ₃COOH	1.3
			4Ff-HPFC-C06	CHF ₂(CF ₂) ₄COOH	1.2
4Ff-HPFC-C07	CHF ₂(CF ₂) ₅COOH	1.4
			4Ff-HPFC-C08	CHF ₂(CF ₂) ₆COOH	1.1
4Ff-HPFC-C09	CHF ₂(CF ₂) ₇COOH	0.7
			4Ff-HPFC-C10	CHF ₂(CF ₂) ₈COOH	0.4
4Ff-HPFC-C11	CHF ₂(CF ₂) ₉COOH	0.2

Known carbon number is the following just easy acquired character of setting, but setting above characteristic will reduce.Infer that this is because the superconducting characteristic that has occurred to cause because of residual carbon is deteriorated.

Although know CHF ₂(CF ₂) _ncOOH and HOCO (CF ₂) _mcOOH has respectively the crackle of preventing effect, but in the situation that considering to maintain superconducting characteristic, more preferably n=2,3,4,5,6 and m=2,3,4,5.

(embodiment 5)

Resulting gel or colloidal sol are dissolved in methyl alcohol (j of Fig. 1), by using volumetric flask, dilute, and obtain the coating solution 5Cs-base in metal ion conversion 1.86M.

In coating solution 5Cs-base, adding with respect to trifluoroacetate solute is the CF of 15 % by weight ₂h (CF ₂) ₃cOOH, CF ₂h (CF ₂) ₇cOOH is as Anti-cracking agent.Using resulting mixing coating solution as 5Cs-HPFC-C05,5Cs-HPFC-C09.

Mixing coating solution 5Cs-HPFC-C05 and 5Cs-HPFC-C09 are added respectively in 100cc beaker, make the depth of water be about 30mm, the orientation LaAlO that two sides is ground ₃monocrystal substrate is immersed in above-mentioned solution, at temperature, is in solution, to mix two hours under 25 ℃, the relative humidity environment that is 30-45RH%, then with the speed of pulling out of 70mm/ second, carries out pulling out of monocrystalline, obtains respectively 1 clotting glued membrane.

The pre-burning curve that resulting gel mould is recorded according to Fig. 7 is heat-treated.In the curve that Fig. 7 records, according to the heat treatment time of 200-250 ℃ being made as to 9 hours 43 minutes, 250-300 ℃ is made as to 1 hour 40 minutes, 300-400 ℃ of curve that is made as 0 hour 20 minutes heat-treated.Oxygen concentration is 10%, and humidification is 4.2%.Resulting pre-burning film is 5Cf-HPFC-C05,5Cf-HPFC-C09.

In order to carry out the internal structure of pre-burning film, observe, carry out tem observation.Figure 10 is used CF in Anti-cracking agent ₂h (CF ₂) ₃cOOH has carried out cross section tem observation image and the high magnification thereof of the pre-burning film of thick-film and has observed image.Figure 11 is used CF in Anti-cracking agent ₂h (CF ₂) ₇cOOH has carried out cross section tem observation image and the high magnification thereof of the pre-burning film of thick-film and has observed image.

The left side of Figure 10 is overall diagram, and the right is enlarged drawing.Be LaAlO below ₃monocrystal substrate, the known state with respect to film surface compact, is the many structures in space near substrate.The pre-burning film of Figure 10 calculates from amount, completely fine and close and void-free pre-burning film if, and thickness should be 2.0 μ m left and right, but is 3.2 μ m from scheming known thickness.Therefore, from amount, calculate, infer that 40% left and right is space.

On the other hand, Figure 11 is also similar structure, and apparent thickness is 3.2 μ m left and right.Now, through calculating, 40% is space.But, to compare with Figure 10, the space in known this space is quite large.

From the hot analysis result of trifluoroacetic acid methanol solution etc., can think the decomposition of the coating solution solute that added Anti-cracking agent take temperature while observing for as follows sequentially.This is sequentially trifluoroacetic acid copper, trifluoroacetic acid yttrium and barium, CF ₂h (CF ₂) ₃cOOH, CF ₂h (CF ₂) ₇cOOH.

Figure 12 is the solution that represents to be successively added with Anti-cracking agent from the left side, the illustraton of model of the state that only trifluoroacetate decomposes during from the gel mould of solution film forming, pre-burning.Although supposition occurs to interact but still dissolves equably with trifluoroacetate in solution.Supposition for there is no the state of methyl alcohol, forms the film of gel state after film forming.

Before Anti-cracking agent is about to decompose, because decomposition has occurred trifluoroacetate, so become as the right figure of Figure 12.Now, Anti-cracking agent is likely liquid condition, can think and also have the effect of oxyfluoride (oxyfluoride) cohesion of promote decomposing.Therefore, can think that Anti-cracking agent is after whole trifluoroacetates decomposes, in the temperature that approaches it, decompose as far as possible, can suppress cohesion, be the coarsening in space.

In this test, being considered to the Anti-cracking agent that decomposition temperature is low is CF ₂h (CF ₂) ₃cOOH.By this reason, thought by CF ₂h (CF ₂) ₇the void ratio of the inside of the resulting thick film of COOH is by CF ₂h (CF ₂) ₃the space of the inside of the resulting thick film of COOH is larger.

Although be this space, on depth direction, the size in the larger space of the distance on distance surface is larger.Can think that the size in this space is critical value when above, will crack.Therefore, used the CF that is considered to have the decomposition temperature larger with the decomposition temperature difference of trifluoroacetate ₂h (CF ₂) ₇although the thick-film of COOH is not to can not get thick film completely, think to have used to be considered to the CF that decomposition temperature more approaches the decomposition temperature of trifluoroacetate ₂h (CF ₂) ₃the thick-film of COOH can more stably obtain thick film.

(embodiment 6)

Think with-(CF ₂) _n-decompose aerification etc. occurs when the pre-burning for basic Anti-cracking agent, residual and dissipation hardly in film.On the other hand, think carried out energetically about to 2008 exploitation with-(CF ₂) _n-for basic Anti-cracking agent tarry carbon component after decomposition, remain in superconducting material, make characteristic significantly deteriorated, although be similar structure, in superconduction film forming, there is a world of difference.In the decomposition of this Anti-cracking agent, need oxygen, but this measures when too much, burning is violent, decomposes likely insufficient when very few.For it is studied, carried out following experiment.

Resulting gel or colloidal sol are dissolved in methyl alcohol (j of Fig. 1), by using volumetric flask, dilute, and obtain the coating solution 6Cs-base in metal ion conversion 1.86M.

In coating solution 6Cs-base, adding with respect to trifluoroacetate solute is the CF of 15 % by weight ₂h (CF ₂) ₃cOOH, as Anti-cracking agent, has obtained mixing coating solution 6Cs-HPFC-C05.

Coating solution 6Cs-HPFC-C05 is added respectively to 100cc beaker, make the depth of water be about 30mm, the orientation LaAlO that two sides is ground ₃monocrystal substrate is immersed in above-mentioned solution, at temperature, is in solution, to mix two hours under 25 ℃, the relative humidity environment that is 30-45RH%, then with 14,40,70, the speed of pulling out of 100mm/ second carries out pulling out of substrate, obtains respectively 4 clotting glued membranes.Using gel mould, as the 6Gf-HPFC-C05-w014(speed of pulling out, be 014mm/ second respectively), 6Gf-HPFC-C05-w040,6Gf-HPFC-C05-w070,6Gf-HPFC-C05-w100.

By resulting gel mould take 4 heat-treat as 1 group of pre-burning curve of recording according to Fig. 7.In the curve that Fig. 7 records, according to the heat treatment time of 200-250 ℃ being made as to 9 hours 43 minutes, 250-300 ℃ is made as to 1 hour 40 minutes, 300-400 ℃ of curve that is made as 0 hour 20 minutes heat-treated.At oxygen concentration, be to carry out for 0.001%, 0.01%, 0.1%, 0.3%, 1%, 3%, 10%, 100% time.Humidification is 4.2%.

When resulting pre-burning film is for example used gel mould 6Gf-HPFC-C05-w040 and partial pressure of oxygen to be 1%, pre-burning film is 6Cf-HPFC-C05-w040-1%.Under this condition with 14,40,70, the speed of pulling out of 100mm/ second is while proceeding to main burning by resulting gel mould, space is assumed to zero theoretical thickness is respectively 510,760,1000 for superconducting film, 1190nm.

Figure 13 is the general chart how outward appearance of the pre-burning film (supposing to infer thickness is approximately 3 times after main burning) of the superconducting film that after the main burning of research, thickness is 510～1190nm changes along with partial pressure of oxygen when pre-burning.Figure 13 is the outward appearance photo of 6Cf-HPFC-C05-w014-1%, 6Cf-HPFC-C05-w040-1%, 6Cf-HPFC-C05-w070-1%, 6Cf-HPFC-C05-w100-1%, 6Cf-HPFC-C05-w014-10%, 6Cf-HPFC-C05-w040-10%, 6Cf-HPFC-C05-w070-10%, 6Cf-HPFC-C05-w100-10%, 6Cf-HPFC-C05-w014-10%, 6Cf-HPFC-C05-w040-100%, 6Cf-HPFC-C05-w070-100%, 6Cf-HPFC-C05-w100-100%.

As can be seen from Figure 13, when carrying out pre-burning under 100% oxygen atmosphere, there is ripple or easily crack in film surface.Even if be not also to obtain flawless film under 10% oxygen atmosphere, but partly crack also from the stagnant liquid in substrate bottom, it is slightly unsettled outward appearance.Although do not represent in Figure 13, in partial pressure of oxygen, be 3% can access stable film forming when following, the pre-burning of take under 1% oxygen shown in Figure 13 is representative, 0.0001%, 0.001%, 0.01%, 0.1%, 0.3%, has also obtained flawless film.In this test, the gas cylinder gas of used argon or line gas only can guarantee 99.9999% concentration, and uncontrollable partial pressure of oxygen is below 0.0001%.

In order stably to obtain film more than 1 μ m to be once coated with thick-film, must control the burning of Anti-cracking agent, known partial pressure of oxygen is made as below 3%.Oxygen amount lower limit is indefinite, but is 0.0001% also to have the effect that prevents that crackle from producing.

(embodiment 7)

For embodiment 5 resulting pre-burning film 5Cf-HPFC-C05 and 5Cf-HPFC-C09, carry out cross section tem observation, but in order to study in the situation that being added with Anti-cracking agent, in the reaction occurring in the pre-burning of TFA-MOD method, whether change, carried out respectively EDS distribution map and measured.

Figure 14 is the result of adding the mensuration of the EDS distribution map carrying out when Anti-cracking agent is carried out thick-film and carried out the cross section tem observation of pre-burning film.This is in order to study the analysis of carrying out with the difference of reacting common TFA-MOD method that cause due to having or not of Anti-cracking agent.

The EDS distribution map of 5Cf-HPFC-C05 as shown in figure 14.Existence ratio to the element of the position of remembering by collimation mark in Figure 14 compares, and result is learnt: formed CuO; Ba-O-F exists can not be called the state mixing of crystallization; And a part coexists with Y-O-F.Also obtain Y-O-F to approach unbodied distributions.Ba-O-F and Y-O-F are considered to bertholide, and known do not have an obvious germination.

On the other hand, also learn CuO germination and along with the time coarsening that becomes.These a series of reactions are reacted with the pre-burning of TFA-MOD method almost and are not changed, even if learn, add CHF in thick-film ₂(CF ₂) ₃cOOH, reacts and also there is no considerable influence for the pre-burning of TFA-MOD method.

Figure 15 means that the bridge portion that passes through to be once coated with the resulting pre-burning film of thick-film technology that the stress causing because of CuO germination has formed space when pre-burning becomes the illustraton of model of causes of crack.Comprehensive experimental fact so far, can think that the model shown in Figure 15 is the model that while being once coated with thick-film, long-time high temperature keeps lower crackle to produce.

First, if add, be once coated with the needed Anti-cracking agent of thick-film, at it in nature as shown in figure 12, when Anti-cracking agent is decomposed, can form space.The periphery in this space is called to bridge portion.Even if add Anti-cracking agent, also there is the reaction identical with TFA-MOD method, so CuO germination.Because of the CuO germination of bridge inside, to bridge portion stress application, when surpassing the boundary of yield stress (proof stress), crack.This is the model shown in Figure 15.

For the effective technology of thick-film that is once coated with shown in this model, be at the temperature that can carry out CuO germination, not keep for a long time.Even if the generation of crackle has the cohesion of CuO particle to participate in, its yield stress boundary also depends on the thickness (or the size in space) of bridge portion, the thickness of bridge portion itself depends on mould (in thick film, compared with deep-seated, putting, space increases), what kind of pore size of therefore can not lumping together all cracks.But as long as thickness is certain and be the bridge portion of identical thickness, the upper limit time of being destroyed by CuO germination also should be determined.Once be coated with in thick-film from this result, having the upper limit of the heat treatment time not cracking.

(embodiment 8)

Resulting gel or colloidal sol are dissolved in methyl alcohol (j of Fig. 1), by using volumetric flask, dilute, and obtain the coating solution 8Cs-base in metal ion conversion 2.13M.

In coating solution 8Cs-base, adding with respect to trifluoroacetate solute is the CHF of 15 % by weight ₂(CF ₂) ₃cOOH is as Anti-cracking agent.Using resulting mixing coating solution as 8Cs-HPFC-C05.

Add respectively 100cc beaker to make the depth of water be about 30mm mixing coating solution 8Cs-HPFC-C05, the orientation LaAlO that two sides is ground ₃monocrystal substrate is immersed in above-mentioned solution, at temperature, is in solution, to mix two hours under 25 ℃, the relative humidity environment that is 30-45RH%, then with the speed of pulling out of 100mm/ second, carries out pulling out of monocrystalline, obtains gel mould 8Gf-HPFC-C05.

The pre-burning curve that resulting gel mould is recorded according to Fig. 7 is heat-treated.In the curve that Fig. 7 records, according to the heat treatment time of 200-250 ℃ being made as to 3 hours 00 minute～12 hours 00 minute, 250-300 ℃ is made as to 0 hour 50 minutes, 300-400 ℃ of curve that is made as 0 hour 10 minutes heat-treated.In A partial experiment, the time of 250-300 ℃ and 300-400 ℃ is made as to twice or 1/2 and tests.Oxygen concentration is 1%, and humidification is 4.2%.

When being made as for example to 4.5 hours 200-250 ℃ of pre-burning time, using resulting pre-burning film as 8Cf-HPFC-C05-4.5 hour.In addition,, while proceeding to main burning under this condition, theoretical superconduction thickness (thickness when voidage is zero) is 1500nm.Also attempted the speed of pulling out of 143mm/ second and 195mm/ second beyond this, but owing to may being the boundary that has arrived dip-coating, from bent moon face with gravity, to mix the speed that coating solution drips slow, so could not obtain uniform gel mould.

The boundary that obtains uniform gel mould with dip-coating, in superconductor and fine and close film, is considered to 1700nm left and right, when than its thick film film forming, and need to be with die coating or wound roll material coating etc.

The guide look having or not about 200-250 ℃ of heat decomposition temperature and crackle is summarized in table 2.

Table 2

?	200-250℃	250-300℃	300-400℃	Crackle
					8Cf-HPFC-C05-3.0 hour	3.0 hour	0 hour 50 minutes	0 hour 10 minutes	Nothing
8Cf-HPFC-C05-4.0 hour	4.0 hour	0 hour 50 minutes	0 hour 10 minutes	Nothing
					8Cf-HPFC-C05-4.5 hour	4.5 hour	0 hour 50 minutes	0 hour 10 minutes	Nothing
8Cf-HPFC-C05-5.0 hour	5.0 hour	0 hour 50 minutes	0 hour 10 minutes	Nothing
					8Cf-HPFC-C05-6.0 hour	6.0 hour	0 hour 50 minutes	0 hour 10 minutes	Nothing
8Cf-HPFC-C05-7.0 hour	7.0 hour	0 hour 50 minutes	0 hour 10 minutes	A part
					8Cf-HPFC-C05-8.0 hour	8.0 hour	0 hour 50 minutes	0 hour 10 minutes	Have
8Cf-HPFC-C05-9.0 hour	9.0 hour	0 hour 50 minutes	0 hour 10 minutes	Have
					8Cf-HPFC-C05-10.0 hour	10.0 hours	0 hour 50 minutes	0 hour 10 minutes	Have
8Cf-HPFC-C05-12.0 hour	12.0 hours	0 hour 50 minutes	0 hour 10 minutes	Have
					8Cf-HPFC-C05-6.0 hour _ 2	6.0 hour	1 hour 40 minutes	0 hour 20 minutes	Have
8Cf-HPFC-C05-6.0 hour _ 3	6.0 hour	0 hour 25 minutes	0 hour 5 minutes	Have
					8Cf-HPFC-C05-6.0 hour _ 4	6.0 hour	1 hour 40 minutes	0 hour 10 minutes	Have

As known from Table 2, total over the pre-burning of 7 hours, when retention time of 200-250 ℃ surpasses 6 hours, can crack.Known in 1.5 μ m film forming, need to amount to following pre-burning in 7 hours.This experimental fact is considered to support the data of the model of Figure 15.

In addition,, in this experiment, also carried out the programming rate of 250-400 ℃ to be made as twice or the experiment of half, but also produced crackle.Think in the curve heating up with the short time, the decomposition of Anti-cracking agent is insufficient and burning has sharply occurred, and has therefore produced crackle, thinks in the curve to heat up for a long time, has caused CuO germination and cracks.

(embodiment 9)

By Eu (OCOCH ₃) ₃, Ba (OCOCH ₃) ₂, Cu (OCOCH ₃) ₂the powder of each hydrate be dissolved in respectively in ion exchange water, respectively with the CF that reacts equimolar amounts ₃cOOH mixes and stirs, and with metal ion mol ratio, 1:2:3 mixes, and obtains thus mixed solution.Resulting mixed solution is added in eggplant type flask, in rotary evaporator, under decompression, carry out reaction and the purifying of 12 hours, obtain gel or the colloidal sol of semi-transparent blue.

Resulting gel or colloidal sol are dissolved in methyl alcohol (j of Fig. 1), by using volumetric flask, dilute, and obtain take Eu as basic coating solution in the coating solution 9Eu-Cs-base(of metal ion conversion 1.52M).

In coating solution 9Eu-Cs-base, adding with respect to trifluoroacetate solute is the CF of 15 % by weight ₂h (CF ₂) ₃cOOH is as Anti-cracking agent.Using resulting mixing coating solution as 9Eu-Cs-HPFC-C05.

Mixing coating solution 9Eu-Cs-HPFC-C05 is added respectively to 100cc beaker, make the depth of water be about 30mm, the orientation LaAlO that two sides is ground ₃monocrystal substrate is immersed in above-mentioned solution, at temperature, is in solution, to mix two hours under 25 ℃, the relative humidity environment that is 30-45RH%, then with the speed of pulling out of 100mm/ second, carries out pulling out of monocrystalline, obtains gel mould 9Gf-HPFC-C05.

The pre-burning curve that resulting gel mould is recorded according to Fig. 7 is heat-treated.In the curve that Fig. 7 records, according to the heat treatment time of 200-250 ℃ being made as to 4 hours 30 minutes, 250-300 ℃ is made as to 0 hour 50 minutes, 300-400 ℃ of curve that is made as 0 hour 10 minutes heat-treated.Oxygen concentration is 1%, and humidification is 4.2%.Resulting pre-burning film is as 9Eu-Cf-HPFC-C05.

Pre-burning film 9Eu-Cf-HPFC-C05, according to the main burning curve shown in Fig. 8, is carried out keeping for 4 hours at 800 ℃ of maximum temperatures, humidification amount is made as to 4.2%, at 525 ℃, carry out below oxygen annealing, resulting superconducting film is 9Eu-Ff-HPFC-C05.

With with above-mentioned same method, replace Eu (OCOCH ₃) ₃, use Gd (OCOCH ₃) ₃, Tb (OCOCH ₃) ₃, Dy (OCOCH ₃) ₃, Ho (OCOCH ₃) ₃, Er (OCOCH ₃) ₃, Tm (OCOCH ₃) ₃, Yb (OCOCH ₃) ₃, obtain superconducting film 9Gd-Ff-HPFC-C05,9Tb-Ff-HPFC-C05,9Dy-Ff-HPFC-C05,9Ho-Ff-HPFC-C05,9Er-Ff-HPFC-C05,9Tm-Ff-HPFC-C05,9Yb-Ff-HPFC-C05.

While utilizing actinobolia to measure for the characteristic of these superconductors under 77K, 0T, result is followed successively by 1.2,1.1,1.3,0.97,0.75,0.68,0.45MA/cm ².Known and YBa ₂cu ₃o _7-xsuperconductor has similarly been realized thick-film.In addition, characteristic is low is considered to due at LaAlO ₃film forming and formed the cause of a/b axle orientation particle on monocrystal substrate.

(embodiment 10)

By Sm (OCOCH ₃) ₃the powder dissolution of hydrate is in ion exchange water, with the CF that reacts equimolar amounts ₃cF ₂cOOH mixes and stirs, and obtains flaxen solution.Resulting mixed solution is added in eggplant type flask, in rotary evaporator, under decompression, carry out reaction and the purifying of 12 hours, obtain translucent slightly yellowish gel or colloidal sol.

Resulting gel or colloidal sol are added to (f of Fig. 1) dissolving completely in the methyl alcohol that is equivalent to its approximately 100 times of weight, this solution is carried out to reaction and the purifying of 12 hours again in rotary evaporator under decompression, obtain translucent slightly yellowish gel or colloidal sol.

Resulting gel or colloidal sol are dissolved in methyl alcohol (j of Fig. 1), by using volumetric flask, dilute, and obtain take Sm as half basic coating solution in the half coating solution 9Sm-h-Cs(of metal ion conversion 0.75～1.30M).

By Ba (OCOCH ₃) ₂, Cu (OCOCH ₃) ₂the powder of each hydrate be dissolved in respectively in ion exchange water, respectively with the CF that reacts equimolar amounts ₃cOOH mixes and stirs, and with metal ion mol ratio, 2:3 mixes, and obtains thus mixed solution.Resulting mixed solution is added in eggplant type flask, in rotary evaporator, under decompression, carry out reaction and the purifying of 12 hours, obtain gel or the colloidal sol of semi-transparent blue.

Resulting gel or colloidal sol are dissolved in methyl alcohol (j of Fig. 1), by using volumetric flask, dilute, and obtaining converting the half coating solution 9Ba+Cu-h-Cs(of 1.52～1.86M in metal ion, to take Ba and Cu be half coating solution on basis).

Mix 9Sm-h-Cs and 9Ba+Cu-h-Cs, take the metal ion mol ratio of Sm:Ba:Cu as 1:2:3 mixes, obtain in the convert Sm superconduction coating solution 10Sm-Cs-base of 1.15～1.45M of metal ion.

In coating solution 10Sm-Cs-base, adding with respect to trifluoroacetate solute is the CF of 10 % by weight ₂h (CF ₂) ₃cOOH is as Anti-cracking agent.Using resulting mixing coating solution as 10Sm-Cs-HPFC-C05.

Mixing coating solution 10Sm-Cs-HPFC-C05 is added respectively to 100cc beaker, make the depth of water be about 30mm, the orientation LaAlO that two sides is ground ₃monocrystal substrate is immersed in above-mentioned solution, temperature be under 25 ℃, the relative humidity environment that is 30-45RH% after solution just mixes the speed of pulling out with 45mm/ second carry out pulling out of monocrystalline, obtain gel mould 10Sm-Gf-HPFC-C05.

The pre-burning curve that resulting gel mould is recorded according to Fig. 7 is heat-treated.In the curve that Fig. 7 records, according to the heat treatment time of 200-250 ℃ being made as to 6 hours 00 minute, 250-300 ℃ is made as to 0 hour 50 minutes, 300-400 ℃ of curve that is made as 0 hour 10 minutes heat-treated.Oxygen concentration is 1%.Humidification is 4.2%.Resulting pre-burning film is as 10Sm-Cf-HPFC-C05.

By pre-burning film 10Sm-Cf-HPFC-C05 according to the main burning curve shown in Fig. 8, under the mixing argon gas that is 20ppm in partial pressure of oxygen, at 800 ℃ of maximum temperatures, carry out keeping for two hours, humidification amount is made as to 4.2%, at 375 ℃, carries out below oxygen annealing, resulting superconducting film is 10Sm-Ff-HPFC-C05.

With with above-mentioned same method, replace Sm (OCOCH ₃) ₃use Nd (OCOCH ₃) ₃, La (OCOCH ₃) ₃, the partial pressure of oxygen during by main burning is made as 0.2～5ppm, oxygen annealing is started to temperature and be made as below 325 ℃, obtains superconducting film 10Nd-Ff-HPFC-C05,10La-Ff-HPFC-C05.While utilizing actinobolia to measure the characteristic of 10Sm-Ff-HPFC-C05 and 10Nd-Ff-HPFC-C05 superconductor under 77K, 0T, thickness is made as 0.50 μ m, is followed successively by 3.1,1.4MA/cm ².About 10La-Ff-HPFC-C05, utilize XRD determining to confirm peak.As above known, with YBa ₂cu ₃o _7-xsuperconductor has been realized thick-film equally.

(embodiment 11)

By Y (OCOCH ₃) ₃, Ba (OCOCH ₃) ₂, Cu (OCOCH ₃) ₂the powder of each hydrate be dissolved in respectively in ion exchange water, respectively with the CF that reacts equimolar amounts ₃cOOH mixes and stirs, and with metal ion mol ratio, 1:2:2.8 mixes, and obtains thus mixed solution.Resulting mixed solution is added in eggplant type flask, in rotary evaporator, under decompression, carry out reaction and the purifying of 12 hours, obtain gel or the colloidal sol of semi-transparent blue.

Resulting gel or colloidal sol are added in the methyl alcohol that is equivalent to its approximately 100 times of weight to (f of Fig. 1) and dissolves completely, when this solution is carried out to the reaction of 12 hours and purifying again in rotary evaporator under decompression, obtain gel or the colloidal sol of semi-transparent blue.Resulting gel or colloidal sol are dissolved in methyl alcohol (j of Fig. 1), by using volumetric flask, dilute, and obtain the half coating solution 11Cs-half-A in metal ion conversion 1.86M.

Due to above-mentioned be the composition of 1:2:3, so for not enough Cu composition, by by Cu (OCOCH ₃) ₂the powder dissolution of hydrate, in ion exchange water, makes itself and CF ₂h (CF ₂) ₃cOOH reacts and carries out purifying and obtain (CF ₂h (CF ₂) ₃cOO) ₂cu.Using this methanol solution as 11Cs-half-B.Mix 11Cs-half-A and 11Cs-half-B, obtain the coating solution 11Cs-base that composition that Y:Ba:Cu is 1:2:3 and metal ion molar concentration are 1.52M.

In coating solution 11Cs-base, add CF ₂h (CF ₂) ₃cOOH is as Anti-cracking agent, and making it is that 15 % by weight are mixed with respect to trifluoroacetate solute.In addition CF, ₂h (CF ₂) ₃the amount of COOH is by (CF ₂h (CF ₂) ₃cOO) ₂the CF that Cu has ₂h (CF ₂) ₃cOO-base is included to be calculated.Using resulting solution as coating solution 11Cs-HPFC-C05.

Add respectively 100cc beaker to make the depth of water be about 30mm coating solution 11Cs-HPFC-C05, the orientation LaAlO that two sides is ground ₃monocrystal substrate is immersed in above-mentioned solution, at temperature, is in solution, to mix two hours under 25 ℃, the relative humidity environment that is 30-45RH%, then with the speed of pulling out of 70mm/ second, carries out pulling out of monocrystalline, obtains respectively 1 clotting glued membrane.

The pre-burning curve that resulting gel mould is recorded according to Fig. 7 is heat-treated.In the curve that Fig. 7 records, according to the heat treatment time of 200-250 ℃ being made as to 6 hours 00 minute, 250-300 ℃ is made as to 0 hour 50 minutes, 300-400 ℃ of curve that is made as 0 hour 10 minutes heat-treated.Oxygen concentration is 1%, and humidification is 4.2%.Resulting pre-burning film is 11Cf-HPFC-C05.Knownly according to the method, also can prevent that crackle from obtaining thick film.

In above-mentioned, the composition of 1:2:2.8 is made as to 1:2:2.9, similarly carry out thick film film forming, resulting pre-burning film is 11Cf-HPFC-C05-B.Known this film also can either prevent that crackle from having obtained again thick film.

(embodiment 12)

In embodiment 11, use Gd (OCOCH ₃) ₃, Dy (OCOCH ₃) ₃replace Y (OCOCH ₃) ₃, with metal ion mol ratio 1:2:2.8 by thick film pre-burning film film forming.Resulting pre-burning film is 12Gd-Cf-HPFC-C05 and 12Dy-Cf-HPFC-C05.Knownly according to the method, also can either prevent that crackle from also obtaining thick film.

(embodiment 13)

By Y (OCOCH ₃) ₃, Ba (OCOCH ₃) ₂, Cu (OCOCH ₃) ₂the powder of each hydrate be dissolved in respectively in ion exchange water, respectively in the mode of reaction equimolar amounts, with mixed C F ₃cOOH and CF ₃cF ₂the mixture of COOH mixes and stirs, and with metal ion mol ratio, 1:2:3 mixes, and obtains thus mixed solution.At CF ₃cOOH and CF ₃cF ₂in the mixing of COOH, prepare in amount CF ₃cOOH amount is three kinds of solution of 90%, 80%, 70%.Resulting mixed solution is added in eggplant type flask, in rotary evaporator, under decompression, carry out reaction and the purifying of 12 hours, obtain gel or the colloidal sol of semi-transparent blue.

Resulting gel or colloidal sol are dissolved in methyl alcohol (j of Fig. 1), by using volumetric flask, dilute, and obtain the coating solution in metal ion conversion 1.86M.To use CF ₃cOOH amount is that the solution that obtains of 90%, 80%, 70% solution is respectively as 13Cs-base-90%, 13Cs-base-80%, 13Cs-base-70%.

In each coating solution, adding with respect to trifluoroacetate solute is the CF of 15 % by weight ₂h (CF ₂) ₃cOOH, as Anti-cracking agent, obtains respectively mixing coating solution 13Cs-HPFC-C05-90%, 13Cs-HPFC-C05-80%, 13Cs-HPFC-C05-70%.

Mixing coating solution 13Cs-HPFC-C05-90%, 13Cs-HPFC-C05-80%, 13Cs-HPFC-C05-70% are added respectively to 100cc beaker, make the depth of water be about 30mm, the orientation LaAlO that two sides is ground ₃monocrystal substrate is immersed in above-mentioned solution, at temperature, is in solution, to mix two hours under 25 ℃, the relative humidity environment that is 30-45RH%, then with the speed of pulling out of 70mm/ second, carries out pulling out of substrate, respectively obtains respectively 1 clotting glued membrane.Using gel mould respectively as 13Gf-HPFC-C05-90%, 13Gf-HPFC-C05-80%, 13Gf-HPFC-C05-70%.

The pre-burning curve that resulting gel mould is recorded according to Fig. 7 is heat-treated.In the curve that Fig. 7 records, according to the heat treatment time of 200-250 ℃ being made as to 6 hours 00 minute, 250-300 ℃ is made as to 0 hour 50 minutes, 300-400 ℃ of curve that is made as 0 hour 10 minutes heat-treated.Oxygen concentration is 1%, and humidification is 4.2%.Resulting pre-burning film is 13Cf-HPFC-C05-90%, 13Cf-HPFC-C05-80%, 13Cf-HPFC-C05-70%.Knownly according to the method, also can either prevent that crackle from also can obtain thick film.

(embodiment 14)

Resulting gel or colloidal sol are dissolved in the methyl alcohol (j of Fig. 1) that is mixed with 10%, 20%, 30% ethanol, by using volumetric flask, dilute, obtain coating solution 14Cs-base-10%, 14Cs-base-20%, 14Cs-base-30% in metal ion conversion 1.86M.

In coating solution 14Cs-base-10%, 14Cs-base-20%, 14Cs-base-30%, adding respectively with respect to trifluoroacetate solute is the CF of 15 % by weight ₂h (CF ₂) ₃cOOH is as Anti-cracking agent.Using resulting mixing coating solution as 14Cs-HPFC-C05-10%, 14Cs-HPFC-C05-20%, 14Cs-HPFC-C05-30%.

Mixing coating solution 14Cs-HPFC-C05-10%, 14Cs-HPFC-C05-20%, 14Cs-HPFC-C05-30% are added respectively to 100cc beaker, make the depth of water be about 30mm, the orientation LaAlO that two sides is ground ₃monocrystal substrate is immersed in above-mentioned solution, at temperature, is in solution, to mix two hours under 25 ℃, the relative humidity environment that is 30-45RH%, then with the speed of pulling out of 70mm/ second, carries out pulling out of monocrystalline, obtains respectively 1 clotting glued membrane.

The pre-burning curve that resulting gel mould is recorded according to Fig. 7 is heat-treated.In the curve that Fig. 7 records, according to the heat treatment time of 200-250 ℃ being made as to 6 hours 00 minute, 250-300 ℃ is made as to 0 hour 50 minutes, 300-400 ℃ of curve that is made as 0 hour 10 minutes heat-treated.Oxygen concentration is 1%, and humidification is 4.2%.Confirmed to form flawless thick film as 14Cf-HPFC-C05-10%, 14Cf-HPFC-C05-20%, the 14Cf-HPFC-C05-30% of resulting pre-burning film.

(embodiment 15)

By Y (OCOCH ₃) ₃, Ba (OCOCH ₃) ₂, Cu (OCOCH ₃) ₂the powder of each hydrate be dissolved in respectively in ion exchange water, respectively with the CF that reacts equimolar amounts ₃cOOH mixes and stirs, and with metal ion mol ratio, 1:2:3 mixes, and obtains thus mixed solution.Resulting mixed solution adds in two eggplant type flasks, carries out reaction and the purifying of 12 hours in rotary evaporator under decompression, obtains gel or the colloidal sol of semi-transparent blue.The gel of an eggplant type flask or colloidal sol are dissolved in methyl alcohol (j of Fig. 1), by using volumetric flask, dilute, obtain the coating solution 15Cs-impure in metal ion conversion 1.86M.

Another gel or colloidal sol are added in the methyl alcohol that is equivalent to its approximately 100 times of weight to (f of Fig. 1) and dissolves completely, when this solution is carried out to the reaction of 12 hours and purifying again in rotary evaporator under decompression, obtain gel or the colloidal sol of semi-transparent blue.

Resulting gel or colloidal sol are dissolved in methyl alcohol (j of Fig. 1), by using volumetric flask, dilute, obtain the coating solution 15Cs-pure in metal ion conversion 1.86M.

In coating solution 15Cs-impure and 15Cs-pure, adding respectively with respect to trifluoroacetate solute is the CF of 15 % by weight ₂h (CF ₂) ₃cOOH is as Anti-cracking agent.Using resulting mixing coating solution as 15Cs-HPFC-C05-impure, 15Cs-HPFC-C05-pure.

Mixing coating solution 15Cs-HPFC-C05-impure, 15Cs-HPFC-C05-pure are added respectively in 100cc beaker and make the depth of water be about 30mm, the orientation LaAlO that two sides is ground ₃monocrystal substrate is immersed in above-mentioned solution, at temperature, is in solution, to mix two hours under 25 ℃, the relative humidity environment that is 30-45RH%, then with the speed of pulling out of 70mm/ second, carries out pulling out of monocrystalline, obtains respectively 1 clotting glued membrane.

The pre-burning curve that resulting gel mould is recorded according to Fig. 7 is heat-treated.In the curve that Fig. 7 records, according to the heat treatment time of 200-250 ℃ being made as to 6 hours 00 minute, 250-300 ℃ is made as to 0 hour 50 minutes, 300-400 ℃ of curve that is made as 0 hour 10 minutes heat-treated.Oxygen concentration is 1%, and humidification is 4.2%.Using resulting pre-burning film as 15Cf-HPFC-C05-impure, 15Cf-HPFC-C05-pure.

15Cf-HPFC-C05-pure is flawless thick film, and 15Cf-HPFC-C05-impure exists serious crackle, and has a large amount of parts from strippable substrate.When use is once coated with thick-film technology by thick film pre-burning film film forming, owing to must forming space part, so the intensity of the bridge portion of periphery becomes problem.Can think that the impurity of solution is the out-phase of acetic acid or Y, Ba, Cu, but it enters bridge portion and weaken intensity, immediately with the thickness that uses high purity solutions to obtain, carry out film forming thus, in this part, also have crackle, as whole generation of film, break etc.

(embodiment 16)

Resulting gel or colloidal sol add in the methyl alcohol that is equivalent to its approximately 100 times of weight (f of Fig. 1) and dissolve completely, when this solution is carried out to the reaction of 12 hours and purifying again in rotary evaporator under decompression, obtain gel or the colloidal sol of semi-transparent blue.

Resulting gel or colloidal sol are dissolved in methyl alcohol (j of Fig. 1), by using volumetric flask, dilute, obtain the coating solution 16Cs-base in metal ion conversion 1.52M.

In coating solution 16Cs-base, adding respectively with respect to trifluoroacetate solute is the CF of 15 % by weight ₂h (CF ₂) ₃cOOH is as Anti-cracking agent.Using resulting mixing coating solution as 16Cs-HPFC-C05.

Use the principle of die coating to mix the orientation LaAlO of coating solution 16Cs-HPFC-C05 in two sides grinding ₃on monocrystal substrate, form the gel mould that thickness is about 40 μ m.At temperature, be to carry out film forming under 25 ℃, the relative humidity environment that is 30-45RH%.

The pre-burning curve that resulting gel mould is recorded according to Fig. 7 is heat-treated.In the curve that Fig. 7 records, according to the heat treatment time of 200-250 ℃ being made as to 6 hours 00 minute, 250-300 ℃ is made as to 0 hour 50 minutes, 300-400 ℃ of curve that is made as 0 hour 10 minutes heat-treated.Oxygen concentration is 1%, and humidification is 4.2%.Using resulting pre-burning film as 16Cf-HPFC-C05.Can think that this film is very thick flawless pre-burning film, but owing to carrying out immediately main burning, so thickness during pre-burning film is not clear.

By pre-burning film 16Cf-HPFC-C05 according to the main burning curve shown in Fig. 9, under the mixing argon gas that is 1000ppm in partial pressure of oxygen, at 800 ℃ of maximum temperatures, carry out keeping for 24 hours, humidification amount is made as to 1.26%, at 525 ℃, carries out below oxygen annealing, resulting superconducting film is 16-Ff-HPFC-C05.The main burning time is grown to needs the time to be above because the not clear cause of thickness.

Figure 16 is the cross section high-resolution tem observation result of 16-Ff-HPFC-C05.It is research cross section tem observation image and in the result of the crystal orientation at each position.

In addition, because pre-sinter process and main firing technique are optimized, so space is completely not suppressed, but known thickness has also reached 5.2 μ m, and on film top, film has all been observed a/b axle orientation on the whole.Only near substrate, having obtained c-axis orientation is because LaAlO ₃on substrate, the character of film forming causes.

But, until film top has all confirmed oriented layer.From being once coated with the model of thick-film, learn that the many pre-burning films in space easily crack and easily break, but space is more difficult to crack more at least.This result has shown can be by TFA-MOD method to be once coated with the superconduction film forming that obtains 5.2 μ m.

As mentioned above, according to embodiment, select CF ₂h-(CF ₂) _n-COOH or HOCO-(CF ₂) _m-COOH(n, m are positive integer) as Anti-cracking agent, to mix with coating solution, the partial pressure of oxygen during by pre-burning is made as below 3%, and the times more than remaining on 200 ℃ were made as below 7 hours, obtains flawless thick film thus to be once coated with.

While utilizing thick film that this technology obtains to make superconduction after main burning, even reach 5.2 μ m.This resulting film is that voidage is 20% and is only the film of 4.2 μ m as superconducting material thickness, but one of reason that crackle produces is considered to the germination due to CuO, if voidage approaches 0%, the destruction possibility of bridge portion diminishes.Therefore, known is the technology that is once coated with the film that can obtain 5.2 μ m.

At present, due at LaAlO ₃on monocrystal substrate, carry out film forming, form the film that is almost a/b axle, and superconducting characteristic approaches zero substantially, but can think by the CeO in the preferential formation of c-axis orientation ₂on intermediate layer, optimize main firing technique, superconducting characteristic improves.In addition, from cross section, TEM has confirmed, the crystal orientation of substrate is consistent with the crystal orientation of the a/b axle orientation particle on film top, even if be this thickness, the orientation of substrate also reaches film top.Therefore, can think by the main burning condition of other optimization and at CeO ₂on intermediate layer, carry out film forming, characteristic improves.

Once being coated with the key point of thick-film as shown in the research of carrying out for embodiment, is 3 following points: (1) Anti-cracking agent and trifluoroacetate stably exist; (2) when pre-burning, suppress the pre-burning under hypoxemia of the violent burning of Anti-cracking agent; (3) stress causing because of CuO germination for the bridge portion that prevents space increases and crackle generation, carries out pre-burning with the short time.In addition, owing to having mixed impurity in coating solution, in bridge portion, can form unsettled part and easily crack, so (4) are also very important by coating solution high-purityization.

By meeting above-mentioned condition, make the film forming and the pre-sinter process that are applicable to continuous film forming technique become possibility.From solution to forming gel mould, within least 24 hours, solution is stable, and particularly, it is also stable that the material that carbochain is little mixes latter 7 days in Anti-cracking agent.In addition, also stable existence of the gel mould of known institute film forming.

(embodiment 17)

Resulting gel or colloidal sol are dissolved in methyl alcohol (j of Fig. 1), by using volumetric flask, dilute, obtain the coating solution 17Cs-base in metal ion conversion 1.52M.

In coating solution 17Cs-base, adding respectively with respect to trifluoroacetate solute is the CF of 15 % by weight ₂h (CF ₂) ₃cOOH is as Anti-cracking agent.Using resulting mixing coating solution as 17Cs-HPFC-C05.

After mixing coating solution 17Cs-HPFC-C05 and mixing in solution, under dry atmosphere, preserve 24 hours, the film build method by application wound roll material coating ratio juris is at CeO ₂(150nm) on/YSZ single-crystal substrate and CeO ₂(70nm)/YSZ (70nm)/Y ₂o ₃(70nm) on/orientation Ni substrate, form the gel mould that thickness is about 20 μ m.At temperature, be to carry out film forming under 25 ℃, the relative humidity environment that is 30-45RH%, using resulting gel mould respectively as 16Gf-HPFC-C05-A, 16Gf-HPFC-C05-B.

The pre-burning curve that gel mould 16Gf-HPFC-C05-A, 16Gf-HPFC-C05-B are recorded according to Fig. 7 is heat-treated.In the curve that Fig. 7 records, according to the heat treatment time of 200-250 ℃ being made as to 6 hours 00 minute, 250-300 ℃ is made as to 0 hour 50 minutes, 300-400 ℃ of curve that is made as 0 hour 10 minutes heat-treated.Oxygen concentration is 1%, and humidification is 4.2%.Using resulting pre-burning film as 16Cf-HPFC-C05-A, 16Cf-HPFC-C05-B.In both pre-burning films, do not crack.

By pre-burning film 16Cf-HPFC-C05-A, 16Cf-HPFC-C05-B according to the main burning curve shown in Fig. 9, under the mixing argon gas that is 1000ppm in partial pressure of oxygen, at 800 ℃ of maximum temperatures, carry out keeping for 12 hours, humidification amount is made as to 1.26%, at 525 ℃, carry out below oxygen annealing, using resulting superconducting film as 16Ff-HPFC-C05-A, 16Ff-HPFC-C05-B.In this superconducting film, do not crack yet.The thickness of superconducting film is respectively 2.4 μ m and 2.7 μ m.Even known, carry out the difference such as intermediate layer, substrate of film forming, also can apply identical thick-film technology.

Key in the film forming of carrying out with TFA-MOD method is: the intermediate layer (or substrate) that the hydrogen fluoride gas that (1) produces when main burning and intermediate layer do not react; (2) ratio of the lattice constant of formed superconductor and the lattice constant in intermediate layer is 93～107%, has Lattice Matching very important.In addition, at CeO ₂during upper film forming, because superconducting layer is with the tilt states growth of 45 degree of direction in face, think is the square root divided by radical sign 2(2 with lattice constant) Lattice Matching of resulting value is to form the key that is orientated superconducting layer.Can think if meet should (1) and (2) condition, also film forming similarly on the intermediate layer that in the past has film forming real achievement.

When the superconducting film of wanting to utilize TFA-MOD method stably to obtain thick film, the manufacturing process of application implementation mode and embodiment is effectively, can stablize and obtain thick film thus.

Although recorded specific execution mode in this specification, these execution modes are only examples, not delimit the scope of the invention.The manufacture method of oxide superconductor in fact, described here also can show as other modes.In addition,, within not departing from the scope of purport of the present invention, can carry out various omissions, replacement and change to apparatus and method described herein.Appending claims and equivalency range thereof comprise form or the modification that falls into the scope and spirit of the present invention.

Claims

1. a manufacture method for oxide superconductor, is characterized in that,

The fluorine-containing carboxylate that dissolving comprises the trifluoroacetate that mixes the metal be selected from yttrium and lanthanide series and barium and copper and obtain, the coating solution that the alcohol that comprises methyl alcohol is solvent is take in preparation, and wherein, described lanthanide series does not comprise cerium, praseodymium, promethium, ruthenium,

In described coating solution, add CF ₂h-(CF ₂) _n-COOH or HOCO-(CF ₂) _m-COOH is as Anti-cracking agent, and wherein, n, m are positive integer,

Use is added with the coating solution of described Anti-cracking agent, forms gel mould on substrate,

The total time that the partial pressure of oxygen of take is the operation below 3%, more than 200 ℃ is the mode below 7 hours, and described gel mould is carried out to pre-burning, forms pre-burning film,

Described pre-burning film is carried out to main burning and oxygen annealing, form the film of oxide superconductor.

2. method according to claim 1, is characterized in that, n=2～6 or m=2～5.

3. method according to claim 1, is characterized in that, contains 70 % by mole of above trifluoroacetates in described fluorine-containing carboxylate.

4. method according to claim 1, is characterized in that, it is more than 80 % by mole that described methyl alcohol is solvent.

5. method according to claim 1, is characterized in that, after adding described Anti-cracking agent till to form the time of described gel mould be more than 60 minutes.

6. method according to claim 1, is characterized in that, after adding described Anti-cracking agent till to form the time of described gel mould be more than 24 hours.

7. a manufacture method for oxide superconductor, is characterized in that,

In described coating solution, add CF ₂h-(CF ₂) _n-COOH or HOCO-(CF ₂) _mcarboxylic acid group in-COOH-material after the H of COOH is replaced by least more than one Y, La, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Ba, Cu is as Anti-cracking agent, wherein, n, m are positive integer,

8. method according to claim 7, is characterized in that, n=2～6 or m=2～5.

9. method according to claim 7, is characterized in that, in described coating solution, further adds CF ₂h-(CF ₂) _n-COOH or HOCO-(CF ₂) _m-COOH is as Anti-cracking agent.

10. method according to claim 7, is characterized in that, contains 70 % by mole of above trifluoroacetates in described fluorine-containing carboxylate.

11. methods according to claim 7, is characterized in that, it is more than 80 % by mole that described methyl alcohol is solvent.

12. methods according to claim 7, is characterized in that, after adding described Anti-cracking agent till to form the time of described gel mould be more than 60 minutes.

13. methods according to claim 7, is characterized in that, after adding described Anti-cracking agent till to form the time of described gel mould be more than 24 hours.

14. 1 kinds of oxide superconductors, it obtains by following method manufacture:

Described pre-burning film is carried out to main burning and oxygen annealing.

15. oxide superconductors according to claim 14, is characterized in that, n=2～6 or m=2～5.

16. oxide superconductors according to claim 14, is characterized in that, contain 70 % by mole of above trifluoroacetates in described fluorine-containing carboxylate.

17. oxide superconductors according to claim 14, is characterized in that, it is more than 80 % by mole that described methyl alcohol is solvent.

18. 1 kinds of oxide superconductors, it obtains by following method manufacture:

Described pre-burning film is carried out to main burning and oxygen annealing.

19. oxide superconductors according to claim 18, is characterized in that, n=2～6 or m=2～5.

20. oxide superconductors according to claim 18, is characterized in that, in described coating solution, further add CF ₂h-(CF ₂) _n-COOH or HOCO-(CF ₂) _m-COOH is as Anti-cracking agent.